Wiring question.

[Kellis135]

Swapping from the 2.9 to a 5.8l and got a custom harness with the engine but it was out of an older ranger. Trying to find a thread on fuse box connector views and wiring for main cab harness, saw a thread earlier can't find it.

 

[RonD]

Welcome to TRS

Bookmark this page for Ranger info: https://therangerstation.com/tech_library/index.shtml


If you have the 5.8l(351) with carb and distributor(picture) then you don't need much wiring.
Just Key on power for the distributor/coil, Red/light green stripe wire

And starter relay(solenoid) wire from key switch, Red/Light blue stripe

Assuming mechanical fuel pump

2.9l wiring here: https://therangerstation.com/tech_library/EDiagrams/files/Diagrams_StartIgnition83to882_9.JPG

Thats from the top link's Electrical section


Charging system here, also in electrical section: https://therangerstation.com/tech_library/EDiagrams/files/Diagram_charging_1991_2.JPG

 

[Kellis135]

I'm actually using the low pressure in tank pump and a pressure regulator so I need the pump to kick on with the key. Thanks for the threads they should help!

 

[RonD]

1988 to 1989 saw some changes

This is the 1988 lay out of relays: https://ww2-secure.justanswer.com/uploads/apjp02/2010-06-22_112812_Graphic.gif

In 1989 they moved the EEC and FP relays under the fuse box, seen here: http://i.fixya.net/uploads/images/db2c160.gif

So you could have either

The FP relay will have a GREEN base/plugin, the EEC relay will have a BROWN base
Thats how you tell which is which in any year

In 1988 Ford used a Fusible Link to power the fuel pump, it runs from starter relay(solenoid) Battery Post, to the FP relay base.

When FP Relay closes the Fusible link power is sent to the Inertia Switch in the passenger side of Cab, on the firewall behind glove box.
On the inertia switch will be a Pink wire, and that runs to the Fuel pump in the tank

In general the FP Relays wire colors are
Fusible link power----Yellow or Black/yellow stripe
Out to Inertia switch---Dark Green/yellow strip

Red wire--12v to activate FP relay comes from EEC relay closing
Light Blue??--to computer, it Grounds this wire to close FP Relay

You should use the FP relay, you just need to do some rewiring
The Red wire on FP relay can be hooked to Key On power, which you will find on the EEC relay base, the Red/green stripe wire should be key on power

Then Ground the FP Relays Light blue wire

So key on closes relay and fuel pump starts

If you want a safer and better system then use an Oil Pressure SWITCH on the engine
Run the light blue wire to that switch
When engine is off, key on the FP Relay will stay open, no Ground
When engine is started oil pressure closes the switch which Grounds the FR relay and it closes, turning on the fuel pump

Carb has a float bowl so has enough gas to start it, so fuel pump down't need to come on until engine starts

This is safer because if there is a roll over, or "accident" that breaks a fuel line, the engine will stall and fuel pump will shut off
It its simply a key on or dash switch fuel pump ON then fuel pump will stay on, and perhaps cause or feed a fire, not a good thing

 

[Kellis135]

I'm starting from scratch. I deleted the entire computer and related harness going off of how the donor ranger was set up. They have a relay in the custom harness I'm guessing for the fuel pump. So ground to the oil pressure switch and since I no longer have an inertia switch I can just hook the power out from the relay directly to the fuel pump power wire right?