Also I did not pull anything vaccume related off of the t-case. Im not sure if what I pulled was the encoder motor or the tccm. I know it sounds bad that I dont kow what it was, but Ihave or "thought" I had a basic understanding of this system, just not all the terms.

 

Ok, you pulled off the encoder motor which shifts the transfer case from 2wd to 4hi and 4lo.
If that's working you won't be able to turn the front drive shaft by hand when you engage 4wd.

The vacuum actuator under the battery just engages the front axles into the front diff and doesn't effect the transfer case


Just to try to help clarify...The encoder motor (that you removed) is an electrically controlled "motor"
The TCCM (transfer case control module) is located inside the truck and is an electronic module, looks like a small computer. This is what recieves an input from the switch on the dash and sends a signal to the encoder motor on the transfer case.

Before you go any further...have you checked "ALL" your fuses? All fuses under the dash and under the hood.

 

That is what I orig. thought, so that is what I was going to replace. The one that I got from the junkyard when hooked up but not bolted up I can lay under the truck with it running and have somone hit the button and the little **** inside the encoder motordoes not turn. I may have gotten a bad one since it was used, so if I would have seen that **** move that would have been locking in the t-case to 4wd? So it is still poss. that the encoder motor is the problem, or does the tccm control the encoder motor? Thank you for the time, Randy

 

Yes, the TCCM controls the encoder motor

 

Yes, all fuses have been checked (1st thing I did). I assumed since I was hearing the clicking from the dash on the pass side that the tccm was working, but it sounds like that may be the problem or I got another faulty encoder motor. i appreciate the help very much, thanks Randy

 

I have to applogize I mistakenly thought you were dealing with the TCCM from some other post I was thinking of, the part that you have is the "Encoder" and it deals with the "range" shifting from 2/4HI to 4LO it will only engage when you are in neutral and coasting under 3mph or stationary.

The front differential locking mechanism is part of the "mode" shifting part of the system, from 2HI to 4HI and back. This part is vacuum operated and can be shifted while moving at according to the repair manual "any forward" speed, I would not go faster than 10mph myself but I don't go offroading to much either (I use it mainly for winter snows).

But when you reinstall the encoder, the bolts should be torqued to 15lb/ft with a torque wrench...

 

Well, I have a different tccm fron the junk yard I am going to try tonight as soon as I am done here at work. I will post the results when I am done, if anyone has any suggestions let me know thanks Randy

 

I installed the new tccm and when the button was hit i could see the encoder move (finallly some progress), but I had my wife start the truck and hit the button while i was under it and she turned the truck back off before the encoder was done cycling now its not lined up to be reinstalled. The button now does nothing, no lights or anything. I have pulled the tccmfuse and am going to try to reset it tomarrow after work, and hopefully it will and I can see if my 4wd will finally work. I read that you only have to leave the fuse out for 3 min and then cycle the ignition 5 times for it to reset, I tried that but maybe I didnt leave it out long enough, idk. Any other suggestions let me have em, and wish me luck, thanks alot guys, (chevy lover) (20blazer00)Randy

 

[ol]Turn OFF the ignition.
Remove the 10amp CTSY LP from the I/P fuse block, and the 20amp ATC fuse from the underhood fuse block.
Important:Replacing the fuse before the specified time may result in not clearing the DTCs.

Wait a minimum of 60seconds before replacing the fuse. Once the fuse is replaced DTC1 will be set in the transfer case shift control module.
Cycle the ignition switch from the OFF position to the RUN and back OFF five times in order to clear DTC1 from the transfer case shift control module memory. [/ol]
Glad to hear of your progress.....oh, you were so close. I don't know if you can turn the slot in the encoder motor to align it with the shaft. If you can, I'd install the encoder motor and then test the system.

 

Well, I went back to the junk yard got another encoder motor and came home and installed it and, guess who has 4wd now <----- this guy. It turns out the first encoder I got was junk, it worked the one time, I guess on a fluke. Thank you guys, chevylover, 20blazer00, for all the help getting this fixed, very much appreciated thanks, Randy