2000 Jimmy 4x4 issues

Of course the most common of problems for the platform, but yet I am lost.

I have a 2000 GMC JIMMY, AUTO, w/4button 4WD. The 4wd started selecting its own state randomly one day while driving. It would just kick in and out of 4wd lo, hi, auto, 2wd... I got it back to 2wd and disconnected the TCCM. I recently bought a new TCCM as the problem was diagnosed to be that part. Well the new model TCCM is installed and nothing works. The selector switch has the backlights on but not the orange selection light.

So I ordered a new switch, 4 button model. Connected it and the backlighting turned on for a split second and then nothing. I can put the old one in and the backlighting turns on instantly.

Please someone give me some ideas on how to repair this, I need to know how to test the components to find the issue.

Thanks.

Of course the most common of problems for the platform, but yet I am lost.

I have a 2000 GMC JIMMY, AUTO, w/4button 4WD. The 4wd started selecting its own state randomly one day while driving. It would just kick in and out of 4wd lo, hi, auto, 2wd... I got it back to 2wd and disconnected the TCCM. I recently bought a new TCCM as the problem was diagnosed to be that part. Well the new model TCCM is installed and nothing works. The selector switch has the backlights on but not the orange selection light.

So I ordered a new switch, 4 button model. Connected it and the backlighting turned on for a split second and then nothing. I can put the old one in and the backlighting turns on instantly.

Please someone give me some ideas on how to repair this, I need to know how to test the components to find the issue.

Thanks.

To test it out you need a good transmission /transfer case capable scanner.
There will be a code set if something is not working right.
You will need to get the code and post back.
Also check all fuses and power feeds.
There may be several fuses that power it up.

I checked all of the fuses when I had the fuel pump issue. I wanted to make sure that every one of them was fine. Found one blown one for the diagnostic port/ cig lighter. Oddest combo for a fuse ever, cant imagine putting both on the same fuse.

Somehow I doubt oreilly auto or even autozone will have a good enough scanner but I will take it to them just to see. I remember seeing the light once and they couldnt get power to the diagnostic port, probably was the damn fuse I replaced.