1990 Ranger will not shift to 4x4 Low... unique situation

[MahLahChee]

Hey all!
Searched everywhere online and couldn't find an answer, so I hopped on this forum to ask some of you wise folks.
I have a very unique Ranger, 1990 single cab, 4.0 v6, automatic but was converted to a manual 5spd. The original electric shift T case was kept. Also has Dodge Dana 60 axles swapped front and rear. Previous owner did all the work, I'm picking up where he left off (and redoing some things done wrong).
Problem: Will shift into 4x4, but not into low range. Low range light blinking and no click or whirr from motor or control module.
Previous owner had the same problem, but decided to remove the electric shifter and opt for a lever you have to turn from underneath the truck in order to shift the case. (I was able to shift into 4x4 and lo using this method) I just installed a new electronic case shifter. Plug was very tight to press together, but got it closed and plugged in all the way. Tested the tcase shift control module (behind drivers seat) and good readout (light blinked 4 times). No Blown fuses.
The only thing I can think of is a brake or neutral sensor is not tripped, which doesn't allow the case to shift. I think this is a shift on the fly 4x4, which is why 4x4hi works, but I've read that 4x4 low can be tricky. The gear selector needle on the dash says the ranger is in Park, but the gear selector handle is not installed (I can move the slider in the steering column freely, but the gear needle does not move from Park)
The biggest issue is the lack of proper factory wiring due to the manual swap.
I have no idea where to start to try and bypass these sensors (if possible) can anyone offer any advice on how to get my system working? I probably skipped some crucial info, so please let me know if you need more details.
I did follow the diagnosis process listed here: " https://www.therangerstation.com/forums/index.php?threads/4x4-system-diag-outline-possibly-something-to-be-pinned.97/ " No luck, which is what makes me suspect a N safety switch or similar...

I'd appreciate any wisdom or tips,
Thanks!
-M

 

[franklin2]

In this link, look at the bottom wide plug. It says in neutral or park you should have a ground on terminal 1. I would strip that wire back bare and hook another wire to it, plug it back into the module, touch your added wire to a good ground and see if it will then shift to 4 low. If it does, you could possibly add a switch to this wire to switch it to ground.

Not sure I would leave this wire permanently grounded, it may be hooked to other things like the computer and make the engine computer think it's in neutral all the time. I have had problems sometimes with this, making the computer act funny.

Here's the link. https://www.therangerstation.com/tech_library/checking_transfer_case_shift_control_module_circuits.shtml

 

[MahLahChee]

In this link, look at the bottom wide plug. It says in neutral or park you should have a ground on terminal 1. I would strip that wire back bare and hook another wire to it, plug it back into the module, touch your added wire to a good ground and see if it will then shift to 4 low.
...
Here's the link. https://www.therangerstation.com/tech_library/checking_transfer_case_shift_control_module_circuits.shtml

Just tried this. Hooked terminal 1 wire on the 8-pin harness connector to the orange ground on the 8-pin pig-tail, then tried the black logic ground on the same connector (where the controller receives ground and power), then just ground on the frame.
Unfortunately had no effect. "low range" still flashes and the motor does not turn.
Forgot to mention in my OP that I do hear a slight click after a few seconds from the controller when pressing "low range" for the first time. This, however, is unlike the 4x4 button, which avails a *click*, *motor whir*, *cli-click*.

 

[franklin2]

The only other thing I see is step 4B in this link. You did step 4A, and simulated a ground on pin one, fooling the module that you were in neutral. But 4B says check that ohm reading for the speed sensor. I figured no signal here would tell the module you are not moving, and it would go ahead and shift. You can't be moving at all when you try to go to 4 low. But they are saying check this resistance, so possibly it has a fail safe and if the sensor is not connected at all it will not work? Don't know. I figure your speed sensor got changed somehow during the swap, or you would have gotten a error code in the engine computer. But possibly somehow the 4x4 module got bypassed? It's worth a check.

Here's the next link with 4A and 4B in it. https://www.therangerstation.com/tech_library/4wd_control_module.shtml

 

[Josh B]

I wouldn't want to count on that manual switch very long, you'll be needing a snorkel

 

[MahLahChee]

The only other thing I see is step 4B in this link. You did step 4A, and simulated a ground on pin one, fooling the module that you were in neutral. But 4B says check that ohm reading for the speed sensor. I figured no signal here would tell the module you are not moving, and it would go ahead and shift. You can't be moving at all when you try to go to 4 low. But they are saying check this resistance, so possibly it has a fail safe and if the sensor is not connected at all it will not work? Don't know. I figure your speed sensor got changed somehow during the swap, or you would have gotten a error code in the engine computer. But possibly somehow the 4x4 module got bypassed? It's worth a check.

Here's the next link with 4A and 4B in it. https://www.therangerstation.com/tech_library/4wd_control_module.shtml

Will try tomorrow morning when I get the chance. I hate to suspect a brand-new shift motor, bull I'll pull that and test it as well to be sure.

I wouldn't want to count on that manual switch very long, you'll be needing a snorkel

Previous owner blew up a few automatic transmissions, so he decided to put a stronger m5odr1 behind the 4.0... I love driving a manual but I'll probably have to sink a stronger auto under the tunnel for crawling. Much much later down the road though ($$$) so gotta make what I've got work.

 

[franklin2]

Anything can happen. But I would think since the system goes into 4 high, that the module and the shift motor are probably good. I thought for sure the special circumstance of having to be in neutral would have let it work in 4 low.

You might want to make sure that pin is grounded (it has to be ground to make the module think you are in neutral) and then try 4 low while letting the truck drift just the slightest amount while in neutral. I do not know if you have ever operated a manual shift transfer case, but sometimes you do have to "help" them go in gear, especially 4 low when things are not quite lined up inside the transfer case. These electric shift transfer cases can be the same. My electric shift Tahoe does go in 4 low better if I let it drift forward ever so slowly while hitting the button.

 

[lil_Blue_Ford]

4lo will not engage in park, only in neutral with your foot on the brake and not moving. Something is not happy about the whole thing. 4lo can sometimes be flakey with engaging. Might be much farther ahead to look for a manual 1350 or 1354 transfer case. If you want a better crawl ratio, add in a doubler.

 

[MahLahChee]

…You might want to make sure that pin is grounded (it has to be ground to make the module think you are in neutral) and then try 4 low while letting the truck drift just the slightest amount while in neutral. I do not know if you have ever operated a manual shift transfer case, but sometimes you do have to "help" them go in gear, especially 4 low when things are not quite lined up inside the transfer case. These electric shift transfer cases can be the same. My electric shift Tahoe does go in 4 low better if I let it drift forward ever so slowly while hitting the button.

look for a manual 1350 or 1354 transfer case. If you want a better crawl ratio, add in a doubler.

My first ranger (‘84 2.8l manual on 36”s) had a manual t case (love that thing) and though it was often very easy to shift I would have to take my foot off the brake to let it roll into gear sometimes.
I have an old t case from that (‘84 BW1350 for the TK5 tranny) that gave me weird binding issues on my ‘84… would I be able to just swap that into my current ‘90 m5odr1 truck? It looks a bit smaller than the tcase I have currently though, so would it be considerably weaker?
I have two 1354s I was going to double (one in the truck atm) so while I prefer manual shift, I’ve already got two electric shift t cases I can double…
Do they make manual shift 1354s?
Going to pick up a multimeter to do some more in-depth investigation and try some of the other tips you guys mentioned.
Thanks!

 

[franklin2]

I had a electric shift I could never get to work reliably. So I put a 3 position spring loaded center off switch on it and ran 12v directly to the shift motor. Hooked it up like it was a electric window. Move the switch one way and it moved the shift motor that way. Move the switch the other way and it moved the shift motor the other way. Worked very well and was very reliable. But you had to get used to bumping the switch to get it in the correct mode.

2wd was easy, it was at the end and you just bumped the switch about 4 times and you knew you were in 2wd.

Same with 4 low, just bump the switch about 4 times and you could feel it engage and knew you were in 4 low.

The tricky one was 4 hi Bump it once from 2wd and you might be in 4 hi, or you might get a little grind from it and not move, so another bump of the switch would usually get it.

I eventually plugged some of the wiring back into the shift motor, went to the shift computer at the windshield and with the diagrams in hand, wired up the shift lights in the overhead console so they helped me know what mode I was in.

 

[lil_Blue_Ford]

My first ranger (‘84 2.8l manual on 36”s) had a manual t case (love that thing) and though it was often very easy to shift I would have to take my foot off the brake to let it roll into gear sometimes.
I have an old t case from that (‘84 BW1350 for the TK5 tranny) that gave me weird binding issues on my ‘84… would I be able to just swap that into my current ‘90 m5odr1 truck? It looks a bit smaller than the tcase I have currently though, so would it be considerably weaker?
I have two 1354s I was going to double (one in the truck atm) so while I prefer manual shift, I’ve already got two electric shift t cases I can double…
Do they make manual shift 1354s?
Going to pick up a multimeter to do some more in-depth investigation and try some of the other tips you guys mentioned.
Thanks!

They did make manual shift 1354s but they aren’t very common.

Sounds like your manual 1350 case probably needs a little rehab

 

[snoranger]

I didn’t read the responses, so sorry if I repeat something that was already said.
If you really think the problem is that the module isn’t seeing neutral, ground the red w/ white stripe wire at the module and see if it will shift into low.

 

[Josh B]

Will try tomorrow morning when I get the chance. I hate to suspect a brand-new shift motor, bull I'll pull that and test it as well to be sure.


Previous owner blew up a few automatic transmissions, so he decided to put a stronger m5odr1 behind the 4.0... I love driving a manual but I'll probably have to sink a stronger auto under the tunnel for crawling. Much much later down the road though ($$$) so gotta make what I've got work.

I'm referring to crawling underneath it to shift, you will need a snorkle
I would take the cover off of that shift motor and check everything for "clean", oiled/greased and working

My truck was sold with a 2WD price due to the shift motor not working. One of the first things I did was buy a new one(Which has been working ever since), and I cleaned up the original and keep it on the shelf
Never had a bit of trouble with any part of it

 

[MahLahChee]

I had a electric shift I could never get to work reliably. So I put a 3 position spring loaded center off switch on it and ran 12v directly to the shift motor. Hooked it up like it was a electric window. Move the switch one way and it moved the shift motor that way. Move the switch the other way and it moved the shift motor the other way. Worked very well and was very reliable. But you had to get used to bumping the switch to get it in the correct mode.

2wd was easy, it was at the end and you just bumped the switch about 4 times and you knew you were in 2wd.

Same with 4 low, just bump the switch about 4 times and you could feel it engage and knew you were in 4 low.

The tricky one was 4 hi Bump it once from 2wd and you might be in 4 hi, or you might get a little grind from it and not move, so another bump of the switch would usually get it.

I eventually plugged some of the wiring back into the shift motor, went to the shift computer at the windshield and with the diagrams in hand, wired up the shift lights in the overhead console so they helped me know what mode I was in.

Definitely will do this if the other suggestions don't work. I like the idea of doing my own wiring where I know exactly what's going on...

I'm referring to crawling underneath it to shift, you will need a snorkle

ahh that makes more sense
Thats why I wanted to do away with it!!!

 

[Josh B]

You can bench test those shifters just like a starter and other motors
I think it was ScottsRanger? had a write-up about it with photos. I got a new one when I got my truck cause I was in a rush, but it suits me to have a spare to just swap out if needed and work on the other one later