Need help with 4x4 switch/module/diagnostics - what now?

Teal4x4 · Dec 22, 2009

I have a '92 4L V8 auto 4x4 and the infamous dash 4x4 switch had stopped working. Instead I'd get a relay clicking sound from the 4x4 electronic module behind the driver-side jump seat, but no 4x4.

I removed the transfer motor, inspected and cleaned it as per the tech info here, but that didn't help. I went through the transfer case/module diagnostics and in doing so found that the 8-way connector to the module had turned brittle and was crumbling to pieces. I figured that was a likely reason for my woes.

Thanks to help here I got a relpacement connector. Fixed the connector issue and now back to the clicking relay symptoms. The connector I guess wasn't the issue.

I started over with the diagnostics. The continuity to the dash 4x4 switch, and voltage to the switch check out. The module blinks indicating its ok. The continuity for the connector in 2H checked out as well. So far so good.

When I did the test for 12V on the orange wire at the shift motor, the DVM went to 0V (not 12V) when the 4x4 button was pressed. Checking volatges at the module, pin 2 (blue) at the gray connector shows 5V (not 12V) when the 4x4 button is pressed. Pin 1 (white) shows 5V (not 12V) when the key is turned to run. The 5V shows at the first "relay" click noise, and dissappears at the second click. The 5V stays there if the 4x4 button is held in.

Any ideas? Am I looking at a shorted motor that is pulling down the voltages, or perhaps a bad module, even though it self-checks as ok?

Any help is very much appreciated as I'm at my wits end :shok:

Thanks in advance

LittleHorse · Dec 22, 2009

hopefully someone will be along to help but if it turns out you need a module I have one that tests out good that came out of mine when I swapped to manual.

rangertoy · Dec 23, 2009

I will send you the module and switch if you need it

Teal4x4 · Dec 27, 2009

Well, I got a couple of good electronic modules, and both give the exact same symptoms as before.

No idea what to do next. I'm thinking it must be the shift motor at this point. Is it possible to "jump" it with 12V to test if its actually working or not?

Any suggestions are very welcome at this stage. :sad:

LittleHorse · Dec 27, 2009

it is possible to connect 12V directly to the motor to tell if it is working or not.

Tech Article said:
There should be a yellow and an orange wire in the motor harness that are a bit larger gauge wire than the rest. Those are the motor power leads. If you apply voltage directly to those wires the motor should spin.

I believe reversing whether orange or yellow gets positive and negative will reverse the direction of the motor...so test it both ways and see how it reacts. You might want to put an inline fuse in your test lead just in case the motor IS shorted, so you don't catch something on fire or burn yourself.

Just so we're on the same page...this is the diagnostic sequence you're using, correct?http://www.therangerstation.com/tech_library/transfercasetroubleshooting.htm

It sounds like you're on the right track with the motor being bad, since everything else seems to check out. From what I can tell the motor also seems to be the most common point of failure. Unfortunately I don't have one of those to sell you, 'cause mines toast!

Teal4x4 · Dec 27, 2009

Yes, same diagnostic article for pre '94s'.

Is there any way I can remove the motor to bench test it? It was connected by wires into the transfer case without any plug so the work I did inspecting and cleaning it was a real PITA as I had to work on the motor and disassemble it underneath the truck. Did a number on my bad back.

Is there a way to remove it? Guess there must be to bve able to replace it.

Roger · Dec 28, 2009

When you had the motor out did you check to see if the rubber bumper on the screw was intact? When my 4x4 module wouldn't work anymore, it was because that bumper had had fallen apart and the "switch" was past its stop... I replaced it with a piece of vacuum hose and it worked fine after that.

Teal4x4 · Dec 28, 2009

Where is that rubber stop? I read about it in the tech articles but didn't see one. I removed the motor out of the gear/indexing housing, exposing the screw shaft. Took it apart and cleaned it and reassembeled it again. Didn't see a rubbr part.

Think I'll remove the whole shebang this time, bench it, and inspect/clean it again. Where would I find the rubbre bump? (anyone know of an exploded diagram for the shift motor & mechanism?)

LittleHorse · Dec 28, 2009

i haven't had mine apart to that extent...

Unfortunately Ford, in their infinite wisdom, decided to run some other wires through the same plug, so the shift motor plug also contains wires for the speed sensor and a single brown wire that runs into the transfer case and to be honest I'm not totally sure what it does. I do know that it doesn't come out. The sensor is easy to remove, but the best way to remove the brown wire is to either cut it, which will then require you to reconnect it when you put it back on, or to try to get the pin out of the back of the connector. I've tried this and have not been successful.

rkneeshaw · Dec 29, 2009

For what its worth, I had the exact same symptoms. Clicking of the module, but no 4x4. The culprit was my electronic shift motor. Instead of trying to repair that though, I just replaced it with a new unit from RockAuto for about $100 I think. Works flawlessly now.

Teal4x4 · Dec 29, 2009

Thanks, yes, its starting to look that way. That's my next step after the bench rebuild of the motor, if that doesn't work.

Andres629 · Dec 29, 2009

Good luck man, hope you can find yourself a good used shift motor around there!

Teal4x4 · Dec 29, 2009

Any '94 or earlier Ranger, Explorer, Bronco II shift motor should work for me, right? Or do I need to get more specific?

LittleHorse · Dec 29, 2009

I don't know if the motors are different between the BW1350 and 1354, but anything '89 or older will have a 1350, so you may want to narrow it down to 90-94. Other than that you should be good, it's all the same in those years on the BII, Ranger and Explorer.

EnglishDan · Dec 30, 2009

DO NOT replace the motor yet!!! Take it completely off the truck. There is only one wire that is difficult when removing from the truck - the brown wire. There is a way to get it out of the connector, but I just cut mine and reconnected it later.
Dismantle the end with more wires going to it, you will pull out a single cog with connectors on one side and the infamous stop on the other, which I bet you has a broken plastic shroud - usual case, this is mine from today...

Whilst this cog is out you will be able to see the worm on the end of the motor... Now jump the motor with 12v + on the yellow and - on the orange and which it spin, reverse the wires and it will spin the other way. If it does not spin take the motor apart and clean the bushes/contacts. If the magnets are broken then it is goodnight! Otherwise if it spins replace the stop with something similar - a bit of tubing. Put the whole lot back together and put it back on the truck - the whole thing will take 2 hours. Disconnect the battery - I read in a thread that it helps the computer forget that it was stuck!!
Worked for me, let me know

Need help with 4x4 switch/module/diagnostics - what now?

New Member

New Member

Member

New Member

New Member

New Member

Member

New Member

New Member

New Member

New Member

New Member

New Member

New Member

New Member

Sponsored Ad

Sponsored Ad

Today's birthdays

Member & Vendor Upgrades

Truck of The Month

Recently Featured

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store

Sponsored Ad

Sponsored Ad

Sponsored Ad

Amazon Deals