1999 Tahoe 4x4 not working

[HowardDog]

So I posted earlier about my timing chain being replaced. Now that she is running good, I need to get my electric 4x4 working again. This was a problem before my timing chain broke that I never fixed.

Now it's deer season and I need my 4x4.

Preface-Last December I put it in 4x4 and it made a popping noise (not too bad) so I pushed it back in 2HI.

Never used the 4x4 again until March when I just decided to put it in 4HI in my driveway and back in 2HI.

The lights on the electric 4x4 dash quit working then and I continued to drive it. Bought a new electric buttons and replaced, still no lights. Bought a TCase control module???(pictured below) and it did not work.

Popping noise gradually got worse when I turned to make it impossible to drive around town. Mechanic took the drive shaft?? out and no more popping noise. He said he needed to fix the transfer case. He said something about it needing a new chain and he manually put it in 2HI and no more popping noise. He still could not get the push button 4x4 to work so he said I needed to take it to a guy that does wiring. He thinks it's the ground wire. I just noticed when I turn the key forward all the lights come on on the 4x4 dash so I'm thinking the ground wire is fine.

Any opinions?

 

[HowardDog]

Any opinions on this? Took it to the mechanic that worked on my engine and he couldn't figure it out either.

 

[east302]

I'd probably take it to a dealer that can actually diagnose the issue. GM has step-by-step tables for diagnosing the "no light" issue.

Or, if you want to give it a go, the diagnostics for this are on alldatadiy.com. An online subscription is about $30/year.

It's a little too much for me to copy and paste or I'd pass it along.

 

[99Vortec]

I would check/trace every bit of visible wire to and from the transfer case/front differential.

Are any tcase fuses being blown?

Your transfercase could very well be internally damaged, but it would be a pisser if something electrical and not mechanical was holding it down.

You mention that all the lights come on your selector switch when you first start the vehicle. I am guessing the red neutral light comes on as well?

good luck!