I'll give it to ya as brief as i can. Please stay with me. Lost 4wd the first time it snowed. Just happened to need tires badly at the time so I took it in for the tires and asked the guy, actually a friend, to take a look at the 4wd system. They, "his guy" had no clue but I did not know at the time. Long story short. He replaced the dash switch and the vac switch on the transfer case. Still no 4wd. I got sick of waiting around watching this jackass fiddle fck around. I jumped in cause I was already there for 6 hours and the thing aint fixed yet. I found a vac leak behind the distributor and spliced the rotton part of it out. I fixed it. I now had 4wd. I thought the trouble was over with. NOT, 2 weeks later another snow storm hits and no 4wd. Here is the deal. I am 100% sure that I have vac at the transfer case, the switch is new, the actuator and cable are fine, the dash switch is new and good ( it is a 3 button switch ) and it worked perfectly fine after I fixed the vac leak. The dilemma is that the switch does not light up and I am certain that it had power before something happened. My guess is that the transfer case module **** the bed because when the dash switch was replaced something was nor grounded to protect the components. I hate just throwing parts at something to fix it. That aformentioned jackass already cost me 175 bucks over a vacumn leak that I found. I kept my mouth shut and just ate the loss. Question? how do you test the module? What is the oem part number? What does the module cost new? Used? I have an account with Alldata for all of my cars. That account does not give me one iota of info on any of this. I cant even find a part number on my GMPARTSDIRECT account. I dropped byt the stealership about an hour ago and the service writer said he thinks it is the module and it would cost 575 bucks for them to fix it if it is the 4wd module. The one thing I did find on ALLDATA.COM account that I have I that the diagnostic time, flat rate is .05. In other words a half hour. Please help me. I know I can fix it myself. Please respond with pertinant info. I dont need guesses. Thanks in advance. Glad you guys are here. Flukey

 

It would be really nice if you could split things up into paragraphs. One big text block is a bit difficult to read through.

There is A LOT of information here about the NV233 transfer case and its controls. If your dash lights are not lighting up, you likely have an issue with the TCCM or possibly just the electrical connections to the TCCM and/or switch in the dash. As far as part numbers, that is only panel away. You never said what year you have though.

And please, next time leave the language out of it. There is no need for that at all. And maybe next time, instead of complaining about shoddy work or the dealership, you could give better details into your problem and try not to come off as a "tell me exactly what the problem is NOW" kind of guy.

 

I am a newby here and iam sorry about not forming my lenghty issue here in a proper litorary form. I also apoligize for trying to get to the point in a fashion that does not waste anyones time. I dont mean to get pushy about opionions. Please bear with me. I am frustrated about this problem.

 

No problem. Frustration happens to everyone.

As far as NV233 information goes, check out the following threads from the Tech Article (DIY) section:
4x4 No Worky.... Maybe this will help.... by Hanr3
OBD2 Non-Automatic Transfer Case Diagnostics by lastcoupe & swartlkk
NV233 transfer case / encoding motor switch by error_401

That last one will have the wiring diagrams for the transfer case. The one for the switch should allow you to test the switch with a regular multimeter set to test continuity.

As far as the part number for the TCCM and switch go, you really should look on the parts that are installed on your truck. The switch just pops out of the dash and the TCCM is behind the passenger kick panel (well it is for the 96+ trucks anyway). The part number should be plainly visible.

Maybe let us know what they are once you find out. I am trying to put together more comprehensive guides to diagnosing and repairing these transfer cases and part numbers would be a nice thing to have.