A few years ago my 4wd wasn't working out of nowhere. So I investigate and I found that the plug for the transfer case motor fell on the shaft and disintegrated the wire of the TCM motor wiring harness.

Anyways now a few years later being a very experienced collision mechanic I change the transfer case motor. Before I changed it I rotated the square piece on the transfer case counter clockwise. I order to fit the TMC.

After everything is done I turn on my car and my car will not move.
-My 4wd Auto lite doesn't light on
-There is no single yellow light say on the 4wd Switch to say what Drive your in.
-The Shaft going into the Transfer case will not move.
-Truck will not move In neutral, reverse nothing.
- 4wd fuse is ok

Will provide the information on my mistake.
Hope that people could also use this thread for information on the 4wd possible not working due to transfer case motor wiring connector falling from its position on top of the Transfer Case onto the Drive Shaft.

Didnt know how else to label this thread but
TransferCase/4WD Issues

 

What year ? Is it a 3 button or 4 button dash switch ?

 

This truck is a 2000 Blazer 4Dr, and it has a 4 button dash switch

 

was the service 4x4 light before the encoder change ? , I believe I read the codes have to be cleared in order for the system to work properly and if not cleared the truck may not move. If you don't have access to a high end scanner that can communicate with the TCCM you will have to look at voltages and such ....it is possible that the TCCM was fried when the wires shorted through. Here is some info on the NP8 from several other posts......The only way to clear codes from your system is with a high end scanner or a terminal type program.

https://blazerforum.com/forum/2nd-ge...-blazer-89044/

 

Your vehicle will not move because you put the transfer case in neutral in order to install the encoder motor. This is the position that a new encoder motor arrives. So it seems the TCCM has not moved your transfer case out of neutral since the repair.

There is more than one fuse for 4WD. The one that would be blown from wiring rubbing on the driveshaft would be the ATC fuse in the underhood relay box (NOT 4WD fuse on the side of the dash).

If that fuse is blown, replace it and evaluate operation.

If still no movement of encoder motor, and no lights stay on in the control buttons - then inspect TCCM connectors for corrosion and clean if necessary. If still doesn't work, either diagnose with a capable scanner or simply replace the TCCM (which may be less expensive than the diagnosis and probably required anyway). Electrical short could have damaged the TCCM.

About the need for clearing codes before operation. In retrospect I think a lot of people have successfully replaced TCCM and/or encoder motor without having the ability to clear codes. I think the need for it is probably more of an urban legend, but I admit that I did clear mine when working on it (because I figured out how to do it). I don't remember seeing anything about the need to do this in the Cardone instructions for the encoder motor or the TCCM. Anyone else care to weigh in on this?