94 4x4 S10 it won't disengage out of 4HI

I have a 1994 blazer 4x4 S10 it won't disengage out of 4HI , The fuse is good

Tonight I went to push the rear wiper and pushed the 4HI by mistake but when I pushed it again to bring it back to 2 wheel drive it stays locked in 4 wheel drive HI, the green and orange light flash when I start the truck (http://www.automotiveforums.com/vbulletin/l) but pushing the switch once it's running there is nothing, no lights or clicking sounds of any kind.
So my question is can I disengage it by hand some how till I find the problem, there is a lot of snow on the road in the city right now but I do need to run this truck on the highway from time to time.
If you have any ideas where to start looking please post

Check all fuses.
And wiring and plugins.
The radio fuse powers the rocker switch.
Power to transfer case shifting is switched on and off by neutral saftey switch and clutch switch and backup light switch and rocker switch.
Even a backup switch plugged in backwards will mess up shifting.

Try putting in neutral or holding down clutch or backing up or rolling forward a little.
And tapping shift motor sometimes may help.
One of the first tests is.
Check rocker switch for 12 volt power and for switching power to transfer case shift module.

Codes can be pulled by grounding pin J to A or grounding pin J on diagnostic connector and counting flashes at rocker switch.
Post back many codes that you may have.

Well the trucks starts so the neutral saftey must be working, back-up lights work, the radio plays just fine but I'll have to look to see if it's not been hot wired someone put a Kenwood in, the rest will have to wait it's been 18F for day time highs and as it is the truck is still driveable


MT-2500 you said this in one other post, with my switch the two lights flash when you start the truck but its dark for 4hi and 4Low after it's running, that could be no power to the switch or what ever the switch is hook to is shot right? does the truck have to be running for the switch from 2wheel and 4wheel or can I hold this switch and then start the truck so at least I'll have power or will it burn something out

MT-2500 said
If the lights on switch do not light up it sounds like a power feed or fuse.
Check all fuses in all fuses boxes.

Does any light come on for a bulb check when key is first turned on?

The lights should come on for a bukb test when key is first turned on.

The transfer case should switch with key on no engine running or with engine running.

The rocker switch should have 12 volt power to it with key on.
And should put out power to the transfer case module when 4W high switch is pushed.
The 4W switch power wire to TCCM is pin A
One push of 4W high should switch in 4W high and when in 4W high another push of 4W high should switch back into 2W.
The 4W low button should put power to the TCCM and it should go to 4W low.

For the wiring and shift test procedures a factory repair manual or a All data sub would help you.
http://www.alldata.com/products/diy/index.html
Have you checked all fuses and power feeds and wiring?
Have you checked for codes?

I checked all the fuses this morning it still didn't work.

This afternoon I pulled the four screws out to get to the switch, I push on the plug and tried it and it seems to work fine now.

But when I went to start the truck the battery was to dead to turn it over, any chance a dead battery could have reset something, how do I do that test that you talked about, I read where you hook a wire from plug 13 to ground, which is 13, I have two on the right side TOP, and three left side BOTTOM, or is it the same as doing codes

Anyways Thanks for you help I'll have to wait till it does it again I guess

Pushing the plug and it started working could be a bad switch or lose plugin or bad wiring.
Next time get a test light and test it before pushing the plug.

Pin 13 is for OBD11 testing 96 up.

94 is OBD1 or test on pin J on yours.
Pin J is bottom row 3 pins over from left to right.

If battery has went dead codes will erase and it is to late to test for codes.
If it acts up again test for codes first and post back codes.
Good Luck
MT

I found this on another forum


***HOW TO CHECK WHAT IS WRONG***

You will probably know when your 4x4 has failed when you needed it in the mud pit. Mine, for instance, failed by not doing anything when I hit the 4HI button. However, it would go into 4LO.

To read the codes for the 4x4 with electric shift transfer case, install a jumper wire from terminals "J" and "A" on the ALDL (12 pin connector under the driver's side dash)

The lights on the 4x4 indicator (switch) will flash in a pattern, there are only 4 codes, one flash is code one, 2 flashes is a code 2, and so on...

Code "1" is "RAM standby power" and is considered normal, may be caused by clearing the codes.
Code "2" is "Encoder fault"
Code "3" is "TCCM motor circuit"
Code "4" is "RAM/ROM failure"

If you have the codes 2 or 3 check all the encoder motor connections at the transfer case, if OK it will need a new encoder motor assembly.
If you have code 4, replace the TCCM.

Make sure all connections are good and no corrosion, and then it's either an encoder or TCCM.

***TO FIX THE TCCM***

The TCCM is located behind the glove box, and is accessed from underneath the dash. To remove, the kick panel and black cover come off. Then a 1/4" screw holds the "brains" in the dash. The middle computer is the Truck's brain, the one on the backside is the TCCM, and on the front is the small ABS computer. Simply loosen the 2 10mm nuts on each side, and they will separate.


***WAYS TO FIX THE ENCODER MOTOR PROBLEM.***

This is the most common problem, and was my problem.

Cheap way - To clear the codes and reset the computer, pull the 5 amp TCCM fuse, located at the bottom of the fuse box. Wait at least a half hour, and then replace the fuse. Turn the ignition key to run, wait for the 4x4 lights to blink, and then turn off. Repeat 5 times, and then start the truck.

Decent price way - I just went and bought a rebuilt encoder motor from a company off of Ebay. Their company is www.northernautoparts.com (http://www.northernautoparts.com/) The part cost me around $140 with a 1 year warranty and $38 core refund when I send the old one back.

Expensive way - buy a brand new one from GM for over $300.

***HOW TO INSTALL THE NEW ENCODER MOTOR***

Lucky way - Only thing that needs to be removed is the encoder motor itself. Tools needed are a 10mm hand wrench and a 8mm and 10mm socket wrench. The 10mm socket will work on the upper and lower bolts, while the regular wrench is needed for the middle bolt. (Tight squeeze). The 8mm socket is for the electric plug.
Then, just pull out, and wiggle it out of the truck. Install in reverse order.

Unlucky way - This means the encoder motor did not just wiggle out. Now the front drive shaft will have to be removed at the transfer case. Then, a yolk puller is needed in order to remove the yolk from the transfer case. Once this is done, go to the directions in lucky way.

This is as much knowledge as I have at the moment about the beautiful setup called the electronic pushbutton 4x4. Thank you to all that have helped me, and hopefully this will help others in fixing the future.

Actually that is what we were trying to tell you.
Are you trying to play us against the other forum?
But anyway..
Thanks for wasting our time trying to help you.

If you want to go to another forum for info more power to you.
But Pease.
Beware of there copy rights and do not copy a post from another forum and post it back on another forum.
Good Luck MT