Its summer and your A/C does not work. That sucks. Well, I have the write up to help you get it back on the road. Keep in mind, my write up only covers 134a systems, specifically in the 1997 4.0 OHV configuration. I believe that 94+ Rangers were outfitted with R134a, but 94 was a transition year, so you might have either R12 or R134a for that year. The overall advice given will apply to other engines and years as well, but you might have to make some adjustments mechanically.

Difficulty: 9 Out of 10 Wrenches:

The reason I am putting this so high is that you really need to pay attention to details. Miss a detail and you can have all of your work be for nothing, including trashing a very expensive compressor. Another difficulty is that messing with the refrigerant cans is dangerous. If you open the wrong valves on the manifold gauge set you can cause the can to explode, possibly severely injuring yourself or any bystanders. Also, keep in mind that the different years of Rangers use different amounts of refrigerant. The 97 has 25 ounces which is a hair over two 12 ounce cans, where the 94 uses 28 ounces (although I have seen 36 ounces for the 94 as well, but I believe that might be for the R12 version) the 1999 uses 30 ounces. This information will also be displayed on the sticker that is on top of the radiator support. Go with that amount if the sticker is still there and readable. I highly recommend that you read this How-To in its entirety before you start the repair, and make sure that you understand each step and what and why you are doing it. If you are unsure of something, ask someone who is knowledgeable, or take your truck to a shop.

Before Job Preparations:

Remove children, small animals, anyone with sensitive ears and anyone else that you do not want to be a target of your frustration and anger toward the Ford engineers that designed this cussing mess…

Disclaimer:

The Ranger Station.com, The Ranger Station.com Staff, nor the original poster are responsible for you doing this modification to your vehicle. By doing this modification and following this how-to you, the installer, take full responsibility if anything is damaged or messed up. If you have questions, feel free to PM the original poster or ask in the appropriate section of The Ranger Station.com forums.

Lets Look at How Your A/C Works:

Before we get to the testing and repair, let’s look briefly at how an air conditioner works. An air conditioner has 5 main parts: The compressor, Evaporator (in the heater box) Condenser (in front of the radiator), Accumulator/dryer (right next to the heater box in the engine compartment) and expansion valve or orifice tube. The engine is what runs the compressor. If there is enough static pressure (the pressure in the system when the A/C is not running) which is over 75 psi, and the electromagnetic clutch is working, when you turn on the A/C, the clutch will engage the compressor which pressurizes the Refrigerant gas. This in turn makes the Refrigerant gas very hot (basic thermodynamics). This hot Refrigerant then goes into the condenser which extracts the heat from the refrigerant using the trucks radiator fan or as the air goes across the condenser when the truck is moving, causing the Refrigerant to condense into a liquid. After the liquid Refrigerant exits the condenser, it goes through the expansion valve or orifice tube into the Low-Pressure side of the system where the Refrigerant starts boiling rapidly as it goes into the evaporator. This boiling causes the liquid Refrigerant inside the evaporator to get very cold as it turns back into a gas (again, basic thermodynamics), and a fan blows over the evaporator which cools the air and because cooler air also cannot hold as much moisture, causes the moisture in the air to condense into water which lowers the humidity of the air as well. After the evaporator the Refrigerant gas goes into the accumulator/dryer. The accumulator/dryer holds excess PAG oil, removes any moisture in the refrigerant using a desiccant and catches any liquid refrigerant that has not boiled into gas yet (Liquid refrigerant going into the compressor will hydro lock it, just like taking water in the intake of the truck). The gas then returns to the compressor to start the cycle all over again. The compressor clutch is controlled by the use of the pressure transducer switches. If the pressure gets too high, the High side transducer (located on the manifold bolted to the back of the compressor) will open and not allow the power to the clutch until the pressure drops back down. The pressure switch transducer which is located on the accumulator/ dryer is open if there is not enough static pressure. If there is enough static pressure, the clutch will engage. You may now wake up, the boring lecture is over.

*Note For Those Doing a R12 to R134a Retrofit:

You will need to replace your hoses, o-rings, and all of the oil. You want to be very careful of what oil you use, as some will not be compatible with the old mineral oil that the R12 systems use! I will not cover retrofitting in this walk through in detail. Also note, if your truck is not a 97, research the capacities for the oil and refrigerant before starting, and make adjustments to these instructions to fit your particular truck.

A word or two about Refrigerants and Oils: I am only doing this walk through for the 94+ trucks that have the R134a refrigerant. If you are looking to do a retrofit as R12 is now illegal to buy or sell, (at least for the average consumer that does not have a proper license to buy and sell R12) you will want to do some more research on what parts you need to replace and how much refrigerant to use, what type of oil to use etc. R134a is a fairly inexpensive refrigerant. You can get it at just about any department store or automotive store from about 7 to 10 dollars for a 12 oz can. Do not use anything but R134a, as other refrigerants can be incompatible with the oil and cause a big mess. Plus, any car that has a refrigerant blend or any weird or exotic refrigerants will not be touched by any mechanic as the recovery process will contaminate his machine and supply of R134a. It is also illegal to knowingly vent the refrigerant into the atmosphere. It must be recovered by a qualified person who has the recovery equipment.

For oil, Ford uses PAG 46 in most of its R134a systems. I recommend getting the Double End Capped PAG 46, as it has much better lubricating qualities than regular PAG 46, plus the Double End Capped PAG oil does not absorb moisture. PAG 100 or PAG 150 are too thick. It is not very much more expensive, and for what you are paying to replace the compressor if getting new, it is worth the 2 or 3 bucks extra. I also got some special oil for the o-rings and fittings called Nylog. It is specifically designed to keep the o-rings pliable and prevent leaks.

Before doing any work on the A/C, make sure all electrical connections (connector at the compressor, and the connector at the pressure switches), fuses and relays are good. Also check the blend doors in the dash, as this is a trouble spot for the Ranger. If any of these are bad, the A/C will not come on or will not work right. Also make sure the belt tensioner is working properly. Check the condenser to see if the fins need cleaning and / or straightening. If your condenser has all of the fins bent over you will have reduced airflow through the condenser and that will decrease the effectiveness of your A/C. You can get a fin comb from Harbor Freight for 5 bucks.

Tools:

You will need access to some special tools for this fix. You will need an A/C manifold gauge set, and a vacuum pump to evacuate the system. You can buy the manifold gauge set at AutoZone or O’Reilly for about $90 or Harbor Freight for about $50. The pump is quite abit more expensive. I recommend borrowing or renting one for this, but Craigslist can be a source as well. I picked mine up on Craigslist for $35. Another option is the Harbor Freight vacuum pump that hooks up to your shop air compressor. This is only $20, but it will not pull a deep vacuum like a regular vacuum pump made for refrigeration will. *note, if using the Harbor freight vacuum pump that attaches to your air compressor, make sure your compressor can maintain at least 110 psi continually for the time that you are using it. Most home compressors do not have this capacity, so if you do not have a commercial compressor, you might be better off buying a used a/c vacuum pump. Also running an air compressor for an extended period of time will consume a lot of electricity, so be aware of that when you get your energy bill. If you are doing the air compressor vacuum route, I also recommend starting and warming the truck up before pulling the vacuum. The residual heat from the engine will help boil out the moisture at a much faster rate. If you warm up the truck before pulling the vacuum you can shorten the amount of time with the vacuum pump turned on. An hour or so should do the trick. (Thanks 4x4 Junkie!)

Other Tools Needed:

• 27mm wrench

• 22mm wrench

• 13mm socket and ratchet

• 11mm deep well socket

• 10mm wrench

• 8mm wrench

• A/C – Fuel line disconnect tools (3 different sizes)

• Digital Thermometer

• Feeler gauge set

• A pick to help remove old o-rings and springlocks

• Orifice Tube Puller

• A/C flush kit which has a bottle that can be pressurized with flush solvent and air and a hose and spray gun. I bought this off of Amazon for about $45

• Four Seasons Dura II Flush Solvent – Expensive at $32 a quart, but this stuff is the best flush compound you can get. You can also use Turpentine as a flush. I bought a quart of Turpentine to do the initial clean and flush, and then used the Four Seasons stuff as the final flush.

• A length of hose that fits over the evaporator outlet and condenser outlet to direct the flush solvent into a catch can.

• Catch can for the flush solvent.

I am going to write this in sections. Each section will be devoted to a specific part that is being replaced. This way you can go to the section you need to fix a specific area of the air conditioning system. At the end will be the Appendixes that will give you some troubleshooting tips and how to flush and charge the system.

For the component replacement sections keep this important fact in mind: If you do any component replacement other than the pressure transducer switches or the clutch, (ie opening the system) you will need to replace the accumulator/dryer. If you open the system to the air for more than a few minutes you must replace the accumulator/dryer. In fact, on a very humid day, a brand new accumulator/ dryer can fill with moisture in as little as 15 minutes, rendering the desiccant inside useless. If your system is good, but all of the Refrigerant has leaked out, you must replace the accumulator/dryer. The reason for this is that the accumulator/dryer is what removes moisture from the Refrigerant. This prevents ice or the water from forming an acidic compound inside your A/C lines and trashing your compressor/ condenser/ evaporator. The good news is that this accumulator/dryer is only about $25 at AutoZone.

Parts:

I bought most of my parts from Rockauto.com. Overall, I spent about $500 in parts. I basically replaced everything but the evaporator, condenser, and the pressure switches. If you are opening the system for whatever reason, you will need to replace the accumulator/ dryer and the orifice tube. Another rule of thumb, if you unhook something with an o-ring, replace the o-ring before you put it back together. They are cheap, and it would suck to have to pull the unit apart again after you get it back together and charged up only to find the old o-rings are bad. If you are replacing the compressor, to have the warranty honored, you will have to show proof of purchase of an accumulator/ dryer, orifice tube, and condenser or have the old condenser flushed. It only takes a few teaspoons of the gunk from the old compressor that is in the lines to wreck the new compressor.

For the cheap minded, I recommend the local junkyard, especially those of you who have access to a u pull yard. I picked up a compressor for under 20 dollars with a 30 day warranty at the local Pull A Part in Indy for my 94 Intrepid a few years ago. The car that you yank your parts from should have no serious front end damage, and I would get a part from a car that has some refrigerant charge left in it. This will tell you the system is intact. For compressors, make sure that the pulley spins freely and that you can turn the compressor with a good firm grip on the hub of the pulley. You will hear it pumping and it should have a little resistance or stiffness in it. What not to get in the yard? The accumulator/dryer and orifice tube. The accumulator/dryer is $25 at AutoZone and the orifice tube is 2 bucks. Both need to be replaced with new anytime you open the system.

Here is the list of parts that I bought to get my Ranger ice cold again:

• Compressor

• Accumulator/ dryer

• Orifice tube

• Refrigerant Line – suction and high pressure with High pressure port (big one that goes from the compressor around the back of the engine to the top of the accumulator/ dryer)

• Refrigerant line – liquid (little one from the condenser to the evaporator)

• O-ring kit (all the new parts that I bought had new o-rings/ springlocks installed, but in case I messed one up…)

Now For The Work.

• Section 1 – Pressure switches

• Section 2 – Electromagnetic clutch and pulley

• Section 3 – Accumulator/ Dryer

• Section 4 – Orifice tube

• Section 5 – Compressor

• Section 6 – Large refrigerant line (suction and high side port from compressor to accumulator/ dryer)

• Section 7 – Small refrigerant line (liquid – from condenser to evaporator)

• Section 8 – Condenser

• Appendix A – Flushing the system

• Appendix B – Prepping a new system for a charge

• Appendix C – Charging the system

• Appendix D – Troubleshooting

• Appendix E – Sources

Parts replacement:

The first thing you need to do in all instances except replacing the pressure transducer switch and replacing the electromagnetic clutch is to have the system evacuated of refrigerant. Remember, it is illegal to knowingly vent any refrigerant into the atmosphere, so if there is a charge left in the system, have it properly reclaimed.

Section 1

Part to be replaced:

Pressure switch transducer (High and Low).

Located on the accumulator/dryer for the low pressure transducer, and right off of the back of the compressor for the High pressure transducer. These parts can be easily accessed from the top of the engine and removed with an appropriate size wrench. These are one of two parts in this section that you do not need to evacuate the system to replace. You need to unplug the wire harness from it and you will need a 17mm open end wrench to remove the low pressure transducer and a 14mm open end wrench to remove the high pressure transducer. Both transducers have an o-ring, be sure to replace the o-ring and coat it with Nylog or PAG oil before putting the new transducer on.

Part to be replaced: Electromagnetic clutch.

This is the other part that does not require evacuating the system.

Tools you will need:

• Safety glasses

• 8mm socket or wrench

• 13mm socket

• Flat blade screwdriver

• Ratchet

• Set of feeler gauges

• 15mm combination wrench

• Torque wrench

• Snap ring pliers

• Plastic or soft face hammer

• Three jaw puller or A/C clutch tool

Procedure:

1. If you are replacing the bearing only, here is the part number from the OEM ford bearing: Nachi 30BG05S5DS

2. Remove the serpentine belt. This is done by placing a 3/8” breaker bar in the tensioner (located in the middle of the engine) and using it to take the tension off of the belt.

3. Disconnect the wire to the electromagnetic clutch.

4. Remove the center bolt from the hub of the clutch assembly (8 mm) you will have to snap the wrench or ratchet quickly to keep the compressor shaft from turning while doing this. You can also get a spanner wrench to hold the compressor from turning.

5. Gently tap the screwdriver between the clutch plate and pulley with the hammer at several intervals around the clutch plate to remove the clutch plate and shim(s).

6. Remove the pulley and bearing assembly by removing the snap ring holding it on.

7. You will also need a three jaw puller or clutch puller tool to assist in removing the pulley assembly. Be careful when setting the jaw on the puller so that you do not damage the electrical connector to the coil. For replacing the bearing, you can remove just the pulley and not the coil if you set the jaws out far enough to just grip the pulley, but the coil is also pressed onto the shaft and will need a puller to remove. The coil is really pressed in hard and will need quite a bit of work to pull off. I do not recommend removing the coil if you just need to replace the pulley, bearing or clutch plate.

8. If there is oil all over the clutch from the compressor shaft, your life just got uglier. See replacing of compressor below. (You technically do not have to replace the compressor, just the seal to the shaft. And that requires removing the compressor…)

9. To install the clutch, if using the same clutch, installation is the reverse of removal. Be sure to align the socket for the power connector in the coil so that it is on top of the connector and sitting in the notch of the compressor housing. You will need to press the coil onto the shaft. A large socket will help seat the coil. Use the rubber hammer to set the pulley back on the shaft.

10. Installing a new clutch assembly or pulley will require you to set the movement distance (air gap) between the plate and the pulley face when the clutch is energized. This movement distance must be between .013” and .033” as measured with a feeler gauge.

11. If the distance between the clutch plate and pulley is outside of the minimum and maximum clearances, you will need to add or remove shims to get it into spec.

12. Torque the center bolt to 12 ft. lbs.

Part to be replaced: Accumulator/ dryer

Located by the heater box on the passenger side

Tools and parts needed:

• Safety glasses

• A/C – Fuel line disconnect tool

• 27mm Combination wrench

• 22mm Combination wrench

• 8mm wrench or socket/ ratchet

• Bottle of PAG 46 DEC oil

• Nylog

• PB blaster

Procedure:

1. Remove the low pressure transducer switch (see Section 1 for details)

2. Soak the nut that is attached to the top tube of the evaporator with PB blaster. Wait a few minutes and soak it again. When you think you have let it soak in enough that you can break it loose, grab the can of PB blaster and hit it again. You might need to repeat this process a few times…

3. Use the 27mm wrench on the nut from the evaporator and the 22mm wrench on the nut for the accumulator. The nut on the accumulator is part of the tube and does *not* turn. It is there so you do not twist the tubing when tightening the nut from the evaporator. Turn the evaporator nut clockwise (as viewed from the front of the truck looking at the firewall. This was a reaaaly tight nut on my truck, with some of the threads showing a fair amount of rust on the accumulator.

4. You may still need to repeat step 1 to get step 2 to work…

5. Disconnect the large refrigerant line from the other side of the accumulator. (This is the line that goes around the back of the engine and then comes underneath the radiator hose and curls in a “U” up to the accumulator.) You will need the largest disconnect tool (white) to unhook this line. Before you put the disconnect tool on, you will need to remove the metal keeper. This can be removed by using your hands or a gentle pry with a small screw driver. They just slide off of the connection point. It will take a bit to muscle the hose off of the accumulator/ dryer as the o-rings will hold it on pretty tight.

6. Take your 8mm wrench/ socket and remove the 8 mm bolt that holds the bracket to the bottom line coming out of the evaporator. The bracket will swing down out of the way.

7. Take the 8mm wrench/ socket and loosen (you do not need to remove it completely) several turns the bolt that holds the clamp around the accumulator dryer.

8. Slide the accumulator/ dryer up and out of the truck. Make sure your new accumulator/ dryer matches the old one.

9. Pour as much oil out of the old accumulator/ dryer as you can into a container. You will need to put in at least this much new PAG oil into the new Accumulator/ Dryer

10. When you are ready to put the new one in (remember, this is the last step you want to do before sealing and refilling the system so do not break the seals on the new unit until you are ready to seal it up and fill the system) be sure that it has all new o-rings and coat them with Nylog or PAG oil. There will be two o-rings at the evaporator end and two o-rings at the refrigerant line end, plus one o-ring for the low pressure transducer.

Part to be replaced: Orifice tube

Located in the lower tube coming out of the Evaporator core.

Tools and parts you will need:

• Safety Glasses

• A/C – Fuel line disconnect tool

• Orifice tube removal tool

• Bottle of PAG 46 DEC oil

• Nylog

• New Orifice tube

• New Accumulator/ Dryer

Procedure:

1. Remove Accumulator/ Dryer (see section 3 for details)

2. Remove the metal keeper and use the second smallest A/C line disconnect tool (blue) and disconnect the short refrigerant line from the bottom line of the evaporator.

3. Use the Orifice tube tool to extract the orifice tube. You can also use a pair of needle nose pliers instead of the Orifice tube tool, but I could not get a grip on the orifice tube with the pliers I had, so rather than fight it for two hours, I went and bought the damn orifice tube tool. Made my life much easier……* Protip: Compressed air can be used to blow the orifice tube out if it is being stubborn. (wish I would have thought of that…Again thanks 4x4 Junkie for that helpful tip)

4. Make sure your new orifice tube matches the old, and pitch the old tube. Don’t bother trying to clean and reuse it, they are only $2.00, it isn’t worth it.

5. Be sure to put some PAG Oil on the o-rings of the new Orifice tube

6. Replace the o-rings and put Nylog or PAG Oil on them when hooking the line back up.

Part to be replaced: Compressor.

Located at the top of the engine on the driver side.

Tools and parts you will need:

• Safety glasses

• 3/8” breaker bar

• ¼” flat blade screwdriver

• 13mm socket

• 8mm combination wrench

• 10mm combination wrench

• Ratchet

• Torque wrench

• Bottle of PAG 46 DEC oil

• Nylog

• New compressor

• New Orifice Tube

• New Accumulator /dryer

Procedure:

1. Disconnect the battery using the 8mm wrench.

2. Remove the rubber air intake pipe from the upper intake and remove the air filter box. You can leave the end that is attached to the inner fender in the truck. You will need to unhook a few sensors to do this. The pipe is clamped to the upper intake with a regular worm screw hose clamp. Use the screwdriver to loosen it several turns, and it will slide off. The air cleaner end has a spring clamp. Just undo it.

3. Remove the serpentine belt. This is done by inserting the 3/8” breaker bar into the square hole on the tensioner. Move the tensioner enough to slip the belt off of the idler pulley in the center of the belt path. Then remove the belt from the compressor. The tensioner is located just below the alternator on the passenger side.

4. Disconnect the connector to the electromagnetic clutch.

5. Unbolt the refrigerant lines using a 10 mm wrench. Pull the lines out of the compressor and set aside. This bolt is kind of hard to get to as the refrigerant lines and the intake manifold block easy access to it. You can break it loose and then by unbolting the compressor from the truck will make it easier to spin out.

6. Remove the four 13mm bolts holding the compressor onto the bracket.

7. The compressor should be free now to take out of the engine.

8. You will now need to clean/ purge the condenser and lines if you are reusing them. See Appendix A.

9. Installation is the reverse of removal. Be sure to put 5 ounces of PAG oil into the new compressor and stand it up on the clutch pulley for about ten minutes or so to ensure that the front seal gets lubricated before putting it in the truck. If you do not ensure that the front seal is properly lubricated, you will leak coolant through the front seal.

11. Be sure to put two ounces of PAG oil in the accumulator/ dryer and an ounce in the evaporator.

12. When placing the new compressor in, make sure that the compressor sits flush on all four mounts of the mounting bracket. If the bracket is warped, straighten or replace the bracket entirely. If you mount it to a warped bracket, it will twist the compressor and cause it to leak.

13. Do not tighten the bolts until they are all in and finger tight, then torque them evenly until they are at 15-21 ft. lbs. DO NOT OVERTIGHTEN!!! Over tightening will cause leaks.

14. When hooking up the refrigerant lines, replace all of the o-rings and coat the new ones with some Nylog or PAG oil. Torque the 10mm manifold bolt to 13 – 17 ft. lbs.

15. Protip: I ended up unbolting my compressor so that I could bolt up the manifold to the compressor easier. It made all the difference, then I retorqued the compressor mounting bolts.

16. After you hook up the hoses, rotate the compressor 10- 12 times by hand to push the oil into the lines.

Part to be replaced: Large Refrigerant line assembly (the one that wraps around the back of the engine).

Located attached to the compressor and wrapped around the back of the engine and attached to the accumulator/ dryer.

Tools and parts you will need:

• Safety Glasses

• A/C – Fuel line disconnect tool

• 10mm socket

• 11mm deep well socket

• Dremel Tool with cut off wheel or grinder

• New Accumulator/ Dryer

• New Orifice tube

• Bottle of PAG 46 DEC oil

• Nylog

Procedure:

1. If available, kick a Ford engineer in the ass for this stupid setup. Otherwise, cuss him out.

2. Disconnect the battery using the 8mm wrench.

3. Remove the rubber air intake pipe from the upper intake and remove the air filter box. You can leave the end that is attached to the inner fender in the truck. You will need to unhook a few sensors to do this. The pipe is clamped to the upper intake with a regular worm screw hose clamp. Use the screwdriver to loosen it several turns, and it will slide off. The air cleaner end has a spring clamp. Just undo it.

4. Remove the Accumulator/ Dryer. (See section 3)

5. Remove High side pressure transducer. (See section 1)

6. Remove Refrigerant line assembly from the rear of the compressor by removing the 10mm bolt that holds it to the compressor.

7. Using the second smallest A/C disconnect tool (blue), unhook the small line that has the high side port from the condenser.

8. Now the fun begins…

9. Unbolt the engine wiring harness from the engine, right next to the driver side valve cover.

10. Unhook the vacuum line from the EGR valve (if equipped).

11. Unhook the brake booster line from one side. Does not matter which side, I choose the booster side because I did not need any tools to pop it out of the grommet

12. Using the 10mm socket, unbolt the engine wiring harness from the firewall.

13. Using the 11mm deep well socket, remove the nut that holds the bracket supporting the wiring harness (right next to the pigtail socket that you just unbolted in step 10) and pull the bracket off. This will now expose an 11 mm stud that secures the ground wire from the harness to the truck body.

14. Using the 11mm deep socket, remove the 11mm stud that secures the ground wires.

15. You will now need to remove the bracket that supports the hose at the rear passenger side of the block. I have no clue how it is fastened to the block, It is two tight of a space for me to get my hands in deep enough to even feel the cussing bolt let alone put a wrench/ socket on it… The bracket comes up from the rear of the cylinder head/ block and wraps around the refrigerant hose and is riveted to itself in a shape of a “P”.

16. My solution…. Take a Dremel tool and grind the rivet off. This will also be a chore as you will have to lean across the engine and the transmission dipstick tube is really close. Once the rivet is ground down, spread the bracket apart enough to drop the hose through the opening.

17. The new hose thankfully comes with a new bracket that is held to the hose with an 8mm bolt. Remove the bracket from the hose and reuse the old one still attached to the engine block and use a zip tie or small bolt to close it back up when reinstalling. I also used a piece of the foam insulation off of the old hose to act as a cushion on the new hose between the bracket and the hose.

18. You now have everything removed/ loosened and ready to pull the refrigerant line assembly out of the truck. Start by wiggling/ finagling the end that was hooked up to the accumulator/ dryer under the radiator hose and heater hoses. This will take some work to get them under these hoses, but then the hose should be free from that side. Gently pull the hose up and work it out from behind the engine. You will come out behind the wiring harness that was bolted into the firewall. Stop.

19. Go to the driver side of the truck and take the end where it bolted to the compressor and move it down and away from the compressor and out from under the wiring harness where it bolted to the engine harness. You will then need to finagle it around the brake booster hose and the throttle cable.

20. The refrigerant line should then come out. If replacing entirely, drain the oil out of the old one into a cup to measure out the same amount of new PAG oil to put in the new hose.

21. Replace all o-rings and coat them with Nylog or PAG Oil

22. Side note, I visited the local Pull A Part and noticed that all the 98 and newer Rangers had the refrigerant line from the compressor to the condenser was secured to the condenser with what looked like an E-7 bolt (basically a reverse torx bolt) Something for the newer Ranger owners to consider…)

Part to be replaced: Small refrigerant line

Located on the passenger side attached to the lower evaporator and the condenser

Tools and parts you will need:

• Safety Glasses

• A/C – Fuel line disconnect tool

• 1/4" flat blade screwdriver

• 8mm wrench

• Tube cutter *optional*

• Inline filter *optional*

• New Accumulator/ Dryer

• New Orifice tube

• Bottle of PAG 46 DEC oil

• Nylog

Procedure:

1. Disconnect the battery using the 8mm wrench.

2. Remove the rubber air intake pipe from the upper intake and remove the air filter box. You can leave the end that is attached to the inner fender in the truck. You will need to unhook a few sensors to do this. The pipe is clamped to the upper intake with a regular worm screw hose clamp. Use the screwdriver to loosen it several turns, and it will slide off. The air cleaner end has a spring clamp. Just undo it.

3. Remove the Accumulator/ Dryer. (See section 3)

4. Remove the Large refrigerant line assembly (see section 6) or move the passenger side end of it out of the way if not replacing the large line.

5. Unhook the line from the evaporator using the second smallest A/C disconnect tool (blue)

6. Unhook the line from the condenser using the smallest A/C disconnect tool (red)

7. Replace the Orifice Tube (see section 4)

8. Be sure to replace and coat the o-rings with PAG oil or Nylog.

9. **Optional** the next steps are recommended if you are replacing the compressor, these will walk you through installing an inline debris filter. If you replace the condenser or there is nothing wrong with the compressor, you do not need to do the following steps.

10. Cut the aluminum tubing on the end that connects to the condenser in the middle. The inline filter kit that I used had a screen at one end and would allow you to put a shortened orifice tube in it, but I just used it for the screen to catch any debris that did not get flushed out of the condenser during the flush process. You can safely remove an inch of the tubing from the middle of the aluminum tube at the condenser end to make up for the length that the filter will add to the line. The flexible rubber part of the refrigerant line also gives you a little bit of leeway when installing the line.

11. The filter that I used came with compressor fittings and rubber gaskets that fit perfectly inside of the filter housing. You choose the size needed for the line. The OEM line that I removed was 5/16” but the new replacement line was 3/8”. Be sure to put Nylog on the gaskets and tighten the compression nuts down good and tight. You might practice with your old line first if replacing the line.

Part to be replaced: Condenser.

Tools and parts needed:

• A/C - fuel line quick connect tool

• 10mm socket

• 8mm socket

• 2” extension for socket

• Ratchet

• Assorted A/C o-rings

• PAG 46 DEC oil

• Nylog

Procedure:

1. Remove small refrigeration line from the passenger side of the condenser. (See section 7)

2. Remove the driver side refrigerant line from the condenser. (See section 6, step 7)

3. Remove the two 10mm bolts that hold the top of the radiator to the front clip/ core support.

4. Lift the radiator up about 3/4” and tilt it back toward the fan. It might make it easier if you remove the charcoal canister, it is held on by a single 10mm bolt and sits up against the driver side inner fender and is kind of up against the radiator support.

5. Keep in mind that there are two transmission lines connected to the radiator on the driver side, be careful with those as you are tilting the radiator back. Also keep in mind that your fan is plastic… and is likely to break if you are not careful…

6. Remove the two 8mm bolts that secure the condenser to the front clip/ core support at the top of the condenser.

7. Tilt the condenser back and carefully slide it out in the gap between the radiator and the front clip/ core support. You might have to move the wire harness that runs along the top of the condenser a little to wiggle the condenser out.

8. Install is the reverse of removal. Be sure to replace all the o-rings when putting it all back together. Remember to replace all o-rings and lightly coat them with PAG Oil or Nylog.

9. Side note, I visited the local Pull A Part and noticed that all the 98 and newer Rangers had the refrigerant line from the compressor to the condenser was secured to the condenser with what looked like an E-7 bolt (basically a reverse torx bolt) Something for the newer Ranger owners to consider…)

*I did not remove my condenser, the above procedure is based upon examining the truck and how it is put together and removing the radiator bolts to see if it could be tilted forward enough for the condenser to be removed. If anyone has experience removing this and has an easier procedure or notices faults or omissions in mine, please let me know.*

Appendix A

Flushing the components.

Tools you will need:

• Safety glasses!

• Flush kit. I used a Mastercool A/C system flush kit. Got it off of Amazon for $45

• Flush solvent Ford recommends a terpine based solvent or Dura Flush for its A/C systems. I used turpentine for the initial flush to get the big gunk out, then the Dura Flush as a final flush, as the Dura Flush solvent cost $32 a quart…

• Shop air to charge the flush kit bottle.

• A metal catch can to reclaim the solvent as it comes out of the component. I used a 32 oz tomato juice can that I cleaned out.

• Paper towels

• Funnel

Procedure:

1. Put your safety glasses on!

2. Do NOT flush a compressor.

3. Do NOT flush an accumulator/ dryer or any hose with a filter permanently attached. Those items will need to be replaced.

4. Place the catch can at the end of the component being flushed. If flushing the component on the truck, be sure to put the catch can at the lowest opening. You may need to put a tube at the outlet end to reach the can. I was able to use the short refrigerant line plugged back into the bottom line of the evaporator, and the condenser was already in such a way that I did not need a hose or tube to extend from the condenser.

5. Assemble the hose and the nozzle on the flush kit.

6. Fill the flush kit bottle with the flush solvent to the half way mark and replace the cap/air fill nozzle assembly

7. Charge the bottle with shop air

8. Put the rubber tip in the opposite end from the catch can. Be sure that you firmly press the rubber tip into the part being flushed so that it seals well, and have the bottle tipped so that the hose is pointing down from the bottle.

9. Squeeze the trigger until all of the solvent and air are released from the flush bottle.

10. Get the catch can and then open the bottle. Put the funnel back in and a paper towel in the funnel to filter the solvent.

11. Put the solvent in the bottle and repeat steps 2 through 8 several times.

12. Once you feel that you flushed it enough, change out the solvent to a clean solvent and repeat steps 2 – 8 again, and then do it again with the Dura Flush as the last step.

13. Let the solvent evaporate out of the system for a few hours

14. I highly recommend putting a filter on the liquid line coming out of the condenser after flushing the condenser. The design of the condenser is such that it will be nearly impossible to flush all of the debris out of it. If you are getting a serious amount of black gunk out of it or your compressor died from the “black death” replace the condenser!

Reasons why you flush the evaporator and condenser...

How to prep your newly rebuilt A/C system for its first charge of refrigerant.

So now you got it all together. You are ready for some Ice Cold A/C again. Here is what you need to do before you put refrigerant in it.

Tools you will need:

• Manifold gauge set

• Vacuum pump for evacuating automotive A/C systems.

Procedure:

1. Hook up your manifold gauge set. Blue to Low side (top of accumulator/ dryer) Red to High side (refrigerant line behind driver’s headlight) Make sure all four of the valves are closed.

2. Hook the vacuum pump to the yellow hose on the gauge set. Make sure the valve on the pump is off.

3. Turn on the pump motor

4. Open all four valves on the gauge set

5. Open the valve on the pump.

6. Let the vacuum run and the low side gauge (blue) should show negative pressure. Let it pump down to as close to a negative full atmosphere as you can (this varies depending on altitude, see chart below) Normal atmospheric pressure is about 28 or 29 inches of Hg for people at 1000 to 1500 ft above sea level.

7. If it is not pumping down, you have a pretty good sized leak in your system somewhere.

8. After it gets down to the proper vacuum level, let the pump run for about 2 hours. If it is very warm and/or humid, let it run longer. On an extremely hot and humid day, let it run for 4+ hours. Running it longer than 4+ certainly won’t hurt. You can cut the time down on running the vacuum pump by starting the engine and letting it warm up to operating temperature. This will help boil out any moisture in the lines quicker. With the engine hot, your vacuum pull time will be about an hour or so, 2 on the very hot and humid days. Again running the vacuum longer won’t hurt it.

*special note for atmospheric pressure/ vacuum and altitude... The vacuum you will be able to pull will be directly related to your height above sea level (see chart below) Your atmospheric pressure is lower as you get higher in altitude. Please use this chart to calculate how much vacuum you should pull for your altitude:

Sea Level = -29.92 in-Hg

500 feet = -29.4 in-Hg

1000 feet = -28.9 in-Hg

1500 feet = -28.3 in-Hg

2000 feet = -27.8 in-Hg

3000 feet = -26.8 in-Hg

4000 feet = -25.8 in-Hg

5000 feet = -24.9 in-Hg

6000 feet = -24.0 in-Hg

7000 feet = -23.1 in-Hg

8000 feet = -22.2 in-Hg

(Thanks 4x4 Junkie!)

9. After it has run for the required length of time, close all 4 valves on the gauge set

10. Close the valve on the pump.

11. Turn off pump. Do not turn off the pump until the valve on the pump is closed.

12. Remove the pump from the gauge set and then remove the gauge set from the car.

13. Replace the caps on the valves on the compressor.

14. Let the car sit for about an hour or so. If you can, leave it sit overnight, this can let you know if you have a slow leak.

15. After letting it sit, hook up the manifold gauge set again. Open the valve on the blue hose. Note the reading. It should still have a -28 inches Hg vacuum. If it does not, you have a slow leak somewhere.

16. If you still have vacuum, Hook up your vacuum pump and pull a vacuum for 5 to 10 minutes (just to be sure) and you can now charge the system using Appendix C.

17. Remember to purge the yellow hose with refrigerant first!

You might be wondering why the vacuum needs to be applied for so long. This is to remove any excess moisture from the system. As the pressure decreases, the moisture will boil from the air easier and be pumped out. You may even see this on a really humid day as the water spits out of the vacuum pump.

Letting the car sit is a good way to test for leaks without having to put refrigerant in, this way you can fix them easier. Another protip given to me by 4x4Junkie is to start the truck and get it up to temperature for several minutes before pulling the vacuum. this will allow the boiling off of the moisture inside the system much quicker.

Charging the system.

Tools you will need:

• Manifold gauge set for R134a automotive A/C Do not opt for the cheap single gauge filler hose that hooks into the low side. You really need to monitor the pressure on both sides to properly fill and test the system. If you do not have and cannot afford the manifold gauge set, rent or borrow one.

• Thermometer

• The appropriate amount of refrigerant for your truck. (97 Ranger’s require 1lb 9oz or 25 Oz.)

Keep in mind, the only way you can accurately put the correct amount of refrigerant in is to evacuate the system and add the recommended amount of refrigerant and then stop. (25 ounces in the case of 1997 Ranger) Unless you have access to very expensive machines that can weigh and meter out the exact amount needed you will want to keep a very close eye on the pressure for both Low and High side, and the outside temperature and the inside the center left dash vent temperature to get you close to the mark. Remember, if you overcharge the system, you can break some expensive parts. A little bit of info that might make your life easier: 1 pound = 16 ounces. The common r134a can is 12 ounces. The sticker under the hood is rated in pounds and ounces (my 97 calls for 1 lb and 9 oz)

Procedure:

1. Make sure all 4 valves are closed on the manifold gauge set.

2. Hook the blue quick connect to the low side valve on the compressor. (Top of the Accumulator/ dryer)

3. Hook the red quick connect to the high side valve on the compressor. (Refrigerant line behind the driver side headlight)

4. Hang the gauge set from the hood making sure that none of the hoses can contact the belts or fan.

5. Let the yellow hose run from the gauge set so that it hangs over the bumper.

6. Take a can of refrigerant and put the tapping device/valve on the can and run the valve in to puncture the can. Keep the valve closed.

7. Attach the valve to the yellow hose.

8. Open the valve on the can

9. At the manifold end of the yellow hose, there should be a shrader valve to bleed off pressure. Open the valve on the refrigerant can and take a small screwdriver and depress the shrader valve until the refrigerant comes out of it. This purges the yellow hose of any regular air and moisture which you do not want in the system.

10. If this is just a recharge or “top off” SKIP to Step 14!!

11. With the truck off, open both the blue and red valves on the hoses next to the trucks refrigerant lines.

12. Open both valves on the manifold portion. This will allow refrigerant to equalize on both sides of the compressor.

13. Close the low side manifold valve.

14. Close the High side Manifold valve. You must do this before going to the next step!!

15. Start the truck, and with the A/C off, check the static pressure. To check the pressure, open both the blue and red valves on the hoses next to the car’s refrigerant lines. DO NOT OPEN THE VALVES ON THE MANIFOLD PORTION!!! If it is above 70 psi, you should have enough Refrigerant to cycle the compressor. A rule of thumb, your static pressure will be close to the outside (ambient) temperature when you are checking it.

16. Put the A/C controls to Max A/C and the blower on the highest setting. Make sure the A/C switch is on.

17. Make sure the engine is running and A/C is on full blast.

18. Look at the low side gauge (blue). It should read above 20 psi and below 55 psi depending on the temperature outside at the time. Your high side gauge (red) will be in the range of 100 psi to 350 psi, depending on how hot it is outside. When the engine fan kicks in, your high side pressure will drop quite a lot.

19. If you are doing a fill with the exact amount of refrigerant (25 oz for a 97 Ranger) you may add the rest of the refrigerant now. 2 full 12 oz cans and a smidge of a third can total. Do not add any more than this!! (if your Ranger is a different year, please look up the proper amount for your truck)

20. For a top off of a low charge system, if your low side pressure is below 20 psi, you can add refrigerant to the system via the yellow hose. Pay close attention to the pressure temperature chart when adding coolant. Something else to consider, if you are doing this on a cool day (below 65 degrees) you can easily overcharge the system and not know it, so I would recommend charging it on a day that is warmer than 70 degrees. If your High side pressure goes above 300 you are in danger of blowing out your condenser…

21. Now that you have the R134a can attached and the valve open, open the blue manifold valve. DO NOT OPEN THE RED ONE UNDER ANY CIRCUMSTANCE AS THE HIGH PRESSURE WILL CAUSE THE REFRIGERANT CAN TO EXPLODE!! Opening the blue valve allows the refrigerant to be pulled into the low side of the compressor to charge the system. Keep an eye on the gauges and charge the system until the low side is just under the low side pressure that correlates to the outside temperature. The high side should not get much higher than 350 psi on a hot day. On a cooler day, both your low and high side pressures will be lower. If you empty your refrigerant can, turn off the blue valve on the manifold before unhooking the empty can. Be sure to purge the yellow hose again when you attach the new can.

22. Protip: if you want the can of refrigerant to load a bit faster, get a pan of hot tap water (no need to put it on the stove to heat it, straight hot water will work) and dip the can in it as it fills. This will heat the refrigerant and make it fill a bit faster.

23. When you reach the desired pressure and temperature settings (as confirmed by your pressure/ temp chart), you should have nice cold air again. Close the blue manifold valve, close the refrigerant can valve (leave the can on the gauge set. This way you will not have to purge it the next time you use it…even if the can is empty, leave it on the gauge set, it will protect the yellow hose from getting contaminated with dirt.)

24. Your air temperature coming out of the middle vent in the dash should read as noted in the below table for the outside temperature listed. Since you cannot accurately measure how much refrigerant is in the system and how much you have added, I would keep an eye out on the temp pressure chart. Once the vents get close to the temps listed, stop filling.

25. Close both valves at the refrigerant lines. Turn the engine off and release the quick connects. Warning: they will be hot, especially the red or high side connection.

26. Replace the caps for the valves and put your tools away, you are done.

Troubleshooting

So let’s say that you have not led a clean life and karma has caught up to you and your truck needs more than a recharge. I will show you how to replace the accumulator/dryer, the refrigerant lines, condenser and the compressor. This next section will be devoted to some simple troubleshooting to find out what is wrong with the A/C.

The first thing you want to do is find out why your A/C is not working. Let’s start with pressure. Does it hold a charge? If it is leaking, you need to find where it is leaking at. Here is how to look for leaks:

1. Following the steps above to recharge the system, put a leak detecting dye refrigerant can in the system. Then after a week or whenever the system leaks out, get a UV light and find out where the leak is.

2. Check the condenser thoroughly, especially looking for places where a rock could have damaged it.

3. Check the connections where the hoses hook into the components, and the compressor around the pulley, valves and hose connections.

4. Make sure the lines are not cracked or bent sharply.

If you have not found the leak in the engine compartment, you have probably have a bad evaporator. It is inside the heater box.

Ok, so I have a charged system, and still no cold air. What now, Einstein?

Well let’s define “charged system”. For the A/C to work there must be around 70 psi static pressure in the system. If the pressure is below 70 or extremely high, the transducers will not send a signal to turn on the clutch. If you have pressure within the 40 to say about 70 psi static pressure range, your compressor should start. If it doesn’t start, check these areas:

1. Make sure the condenser is clean and not clogged with bugs, dirt, small animals, children etc..

2. Also make sure the fins are straight and allow air to pass through. You can get a fin comb to straighten them out if needed.

3. Make sure all the fuses for the A/C compressor and blower are good.

4. Check the relay for the compressor clutch. You can do this by swapping it with other relays (Horn relay is a good one to use)

5. Check to make sure all connectors are getting good connection, especially the clutch coil and Pressure transducer switch harness.

6. Take an ohmmeter and check for continuity on the clutch coil by unhooking the connector and checking for continuity between the terminals. If there is no continuity, your electromagnetic clutch is bad and will need replaced.

7. If all the above check out, you are left with a bad pressure transducer switch or wiring harness to the compressor or pressure switches.

So we now know that it is charged, everything checks out mechanically and electrically. The compressor kicks in and turns, but it just does not put out cold air. Well, I hate to tell you this, but your compressor is worn out and is not building pressure on the refrigerant. You will need to replace the compressor. This can also be confirmed by the manifold gauge set. If the pressure differential between the high and low side is very small, with typically fairly high low side pressure and low high side pressure, the compressor is shot.

So what say the compressor snaps belts or continuously squeals? The compressor is probably locked up; you will need to replace the compressor.

Appendix E

Sources:

Altitude atmospheric pressure chart for calculating how much vacuum to pull:http://www.engineeringtoolbox.com/ai...ure-d_462.html

Thanks to:

4x4Junkie

Cvar

for their input in making this How-to more precise, easier to read and just all around better.

Hope this helps you get your A/C going again.

AJ