HELP with 4WD.. probably electrical

[aaronsjewelry]

Tried to engage my 4WD the other day and got nothing. No lights on the dash and certainly no 4WD. I recently removed part of the dash to install a new stereo, so I thought maybe I just forgot to plug the 4WD switch back in when done with install. I checked it and it SEEMS to be fine. How do I go about diagnosing the problem from here? Which wires do I test for power or continuity? Incidetally the 4WD has always worked up until now all be it not very often. I only use 4WD drive 3 or 4 times a year.

[aaronsjewelry]

[Midnightrider]

Check the fuses, sounds like one blew while you were working on your radio.Look carefully their easy to miss.

[aaronsjewelry]

any idea of which fuses specifically? I checked # 111 it was fine... Also, I have power going to the switch and the vacuum system doesnt seem to have any leaks, (assuming anyway because my AC/Defrost all works normally)

Now I'm leaning towards a problem with the tranfer case motor or it's connections only I dont really know how to test this and I hate to buy a new one just to see if thats the cause.

Any expert opinions/advice would be greatly appreciated

[Midnightrider]

I don't know which fuse it is, i'll try and look at mine tonight but it was one of the big square type fuses and i had to look really close to see it you can't get a test light on it to test it. You might check to see if the plug is loose on the transfer case. Mine was loose and i just pushed it back on. Don't know how they come loose, but they do.

[Midnightrider]

Check # 17 fuse.Then check wire plug on Transmission.

[aaronsjewelry]

All fuses are good, Did a resistance check on the switch and all values were in the normal range, the plugs on the transfer case motor were very clean and connected snuggly. now I'm reading about a 4WD control module. Thats the next thing to test after the switch test ONLY I dont know where the hell that is. (some threads have said passenger side kick panel, others behind the glove box) I wish I knew EXACTLY what I was looking for

[aaronsjewelry]

its behind the glove box up under the dash, says sport utility pickup 4x4(or something like that) on it. Does anybody know how to figure out if this is the actual problem, aside from buying a new one to see if the problem goes away?

[mofasta]

Try taking your t/c motor off and using a 12v power source on the 2 prong side of motor to cycle it back in forth and the make sure you have it back in same position as when you remove it and put it back on. This will let you know that the motor function of it is good .not to say that the other plug which controls position could be bad, mine was stuck in 4wd and this is wht I did and it started working again, I think from not using them very much they get sticky on either motor or positioning circuit, hope this helps and try to engage your 4wd once a week just to keep things moving.

PS-the Tcase motor is turned on by the GEM module Fords version of a body control module, usally what happens is the contact plate which the cover can be taken off and cleaned gets crap in it causing the interm operation of the TCCM.
__________________


AJ

[BigBlueDually]

Here are some schematics for the 4wd. These should help you trace out the problem.