Electric Shift Not Working ?

[Mike B]

92 Ex How do you trace out too find the problem ?

Anyone have the steps from the Shop Manual please email them to me tacktech@westol.com

I replaced the Motor and it was not the problem !

Took the old one apart and its fine put 12v to the motor wires and it spins fine where do you look now ?

All fuses are good !


I tried the turn key too Run and hit the reset botton by the Washer Tank in the left rear and push the 4 wheel botton and no lights where too look next ?

Thanks

 

[Pheonixx77]

well hey if you find out let me know, i've got a real similar problem

 

[TPLYNCH]

If you haven't been yet, go here - Dead Link Removed

 

[DeRocha]

I am presently working on mine (as of last night). I have read thru the edu doc several times. I know my shift motor works (I've tested it in both directions), but it still will NOT operate when pushing the 4x4 button. I believe this has to do with the 4x4 position sensor. I have removed the whole assembly, cleaned the brushes, and armature. The stop attached to the geared position sensor was gone (just like everyone elses). I made a new one out of rubber tubing.

From what I can tell the cap of the sensor cover has several electric connectors on it. This cap can be loosend and rotated left/right which will cause different parts of the sensor to contact the connections on the geared part. The only variable should be the cap. The other components should only go in one way... After reinstallation I verified my truck was set to 2H and re-installed the cover loosely. I then used my meter to test the pins. I didn't get any continuity for the 2H settings (which I should have). Because I have removed everthing I know the T case is in 2H. I then rotated the sensor cover a little to the left and re-tested.. Magically all continuity settings for 2H registered correctly!. I then confidently buttoned up all the loose connections and re-connected the battery. I started up the X and pushed 4x4...I was disapointed...All I heard were the relays being switched in the rear compartment.

I will give it another try tonight...

 

[Mike B]

Well sounds like you got better results than me !

When i try the bottons after installing a New Motor I get nothing ! Not even relay clicks !

I just wonder if the control Module is Bad or the Dash bottons are bad but how do you tell ?

Both fuses are good !


Where else do you look ?

MIke

 

[DeRocha]

On 1st gens the 4x4 module is in the trunk area next to the washer bottle. To run a self diagnostic: Unplug the upper and lower wiring connectors from the left side of the unit. With the ignition key set to run press the white button on the bottom of the module..A red led will flash if the problem is in the actuator/motor assembly, or remain steady if the problem is with the module.

I have been "playing" with mine for the past 2 hours. I have verified the 2W position by using an ohm meter and testing the wiring connectors. I then rotated the cover slightly to the left and retired the 4x4 button..Nada I just hear the relays going off for a few secs. I then rotated the cover back to the right (again testing via ohm meter) and tried 4x4 again nothing.. I then removed the cover competely exposing the toothed gear. I connected 12v to the motor directly and the toothed gear moved (slowly).. I wonder how fast it should move and whether my motor is getting old and on its way out??

 

[Pheonixx77]

quote:

On 1st gens the 4x4 module is in the trunk area next to the washer bottle. To run a self diagnostic: Unplug the upper and lower wiring connectors from the left side of the unit. With the ignition key set to run press the white button on the bottom of the module..A red led will flash if the problem is in the actuator/motor assembly, or remain steady if the problem is with the module.

ok so what does it mean if i disconnect the lower connector and dont get anything? no light on or blinking....nothing nada zip zero zilch. there is no dash lighting for the switch currently (it does not light up with the rest of the dash, could that be related?)

 

[DeRocha]

Did you unplugg both the upper & lower connectors?
Are your fuses good...I believe there are 3...

 

[DeRocha]

I found this extra info regarding testing the rear control module. Pull off the 2 connectors and turn the key on. Press the white reset button on the module. The red LED should blink several times then Stop. If the LED didn't flash or kept flashing then the control module is damaged.

 

[DeRocha]

My shift motor is Now Working!

I had removed it (again) and really cleaned the armature. I must admit my first cleaning was with a Qtip and some alcohol (I didn't want to screw things up). My second cleaning was 100% complete. I used fine steel wool and buffed the copper contacts until they were new and shiny.

I also used the steel wool to buff the contacts under the selector gear cover, and used some alcohol to ensure there was no film on the electric contacts. I used compressed air to ensure no steel wool was hanging around. The Next pic shows small hobby spring clamps holding the brushes against their springs. This makes installation easy.

Looking back I believe my problems were two fold:

1) The plastic stop on the selector gear was destroyed. This in affect causes the selector gear to travel beyond the stop and fall outside the sensors range. The 4x4 module in the rear trunk is then unable to determine the position of the selector shaft (2H,4H,4L) so it shuts down in a fail safe mode.

2) The dirty contacts on the armature cause the motor to work less efficiently. Don't be afraid to clean them good.

To make things line up easily I verified the selector shaft was in 2H and installed the shift motor without the selector gear. I then slid the selector gear into place over the worn gear it only goes in ONE way and slides right on. It will be a PITA if you try to install the unit with the gear unit. I then installed the cover without the bolts and used my meter to verify (2H) continuity. If neccessary Rotate the cover left/right to get continuity. Connect the wiring harness and TEST the system. You may need to reset the rear control module. If ok then install the cover bolts.

Cool info The T-case can manually be shifted. You can removed the shift motor to expose the selector shaft. Rotate the shaft to 4H and bingo, you're in 4H. Rotate it back and your back to 2H, it is that easy. The selector feels spring loaded so you can positively feel it "snap" into each position 2H,4H,4L. So don't be afraid to move the selector thinking it will get "out of position".

 

[Pheonixx77]

been awhile since i looked at ths post, i am allmost gonna give up and take t to a shop. i am frustrated as hell with my 4wd system. where are these fuses you mentioned? i looked under the dash all the fuses are good. The fuses are also good n power dst box under hood. the only things i did before the 4wd went down was : pulled into garage in 4wd (i had to go up a hill in snow to get there) left it n 4wd disassembled dash to put in indiglo gauges, reassembled dash and plugged n dash switch for 4wd. i have since removed the dash again to make sure i did not forget anythng, loosen anything etc. all of that is good. the switch was acting funny before it went...lights for 4wd were dim but both were on, just not as bright as when 4wd is engfauged. i get no lighs on dash, hear no clckng sounds when trying to engauge, and the GEM (box in rear of truck) does not do anythng when i test it. i removed both connectors tested it, i also tred it with one connector off at a time. still nothing. i figure since it worked fine before the only problem i face is electrical, either the switch or the GEM. but i dont want to start throwing $$ at the truck not knowing whats wrong.

EDIT: the switch no longer illumnates when lights come on nor do the lights come on like before, they were dim but on, it's like it was dying slowly or something.

 

[DeRocha]

Are you testing the GEM with the Key on?

 

[Pheonixx77]

yup, i have tried it every way imagneable KOEO , KOER, disconnect this wire this time, disconnect that wire etc...nothing. is the box not getting power somehow? if so how do i test to see if the box is getting power?

 

[DeRocha]

Do you have a wiring diagram of the shift control system? I can e-mail you one if you don't. Use a meter and check the following wires on the rear 4x4 module for power:

W/P (white/purple) is connected to fuse #11 (15amps) Hot in accy or run

BK/W (black/white) is connected to power dist fuse #9 (40Amps) Hot @ all time

 

[Pheonixx77]

well kinda but my haynes manual is worthless on this one "typical 4wd wiring syatem" LMAO but are there other fuses besides power dist box and fuse panel inder dash? Pheonixx@nc.rr.com tell me where to find all (three? i hear ) fuses so i can track this down, i know it has to be electrical since everything worked like a day before it went to hell.