Was able to change the seal without taking the transfer case out. Just slid it back and removed the retainer. The seal was brittle and just crumbling. So fixed that and the vacuum switch ant the 4 wheel drive now works... Sometimes. Well it did... It's intermittent and I will need to trouble shoot that. The HVAC vacuum plug that goes on the defroster selector is leaking. Tried to make a sleeve, but it may be the switch itself. Will not go into low. Tried t reset computer and now it won't light up at all. Worked fine just sitting in garage but once I took it out it freaked out and now nothing. Mechanically it's good because I did it get it to work fine. Who knows.

 

Well now I did it. After working fine in the garage it quit working on the road. Pulled the 4x4 switch out to remove the dash to check for leaks and when input it back in no lights, no nothing. Then it got stuck in 4x4. Tried to reset the tccm pulling fuse, no dice. Pulled plug off the tcase, put it back on and light blinked once then never came on again. Tried pulling codes and when I grounded pin 13 I got no lights at all. Pulled batt tray and took vacuum off actuator and was able to get it to go back into 2hi. Still no lights. Figured I could drive to work in 2 hi fine, then power steering pump let go in the drive way. I gave up.

I'm leaning towards the tccm, well I'm leaning towards this truck hating me actually. But I have no idea why taking the plug off the tcase would destroy a tccm that was working before. Might be the encoder but hell I dunno. I got no lights so I really cant say for sure what is going on. Ideas or words of encouragement, beer, pics of hot girls would help. Trying to get my thoughts together for this weekend and round two. My Camaro was not happy it had to take me to work in a hurricane. Taking the plug off seemed to have some effect so I am leaning on electrical now. Remember, I was fixing a vacuum leak and the tcase switch and seal were bad. No all of a sudden nothing works at all. Before it took a bunch of tries, but it would work and the lights responded as they should. Now they never light even when turning the truck on. Bout to drive it off a cliff.

 

check for corroded tccm pins, check for bent pins at the t-case connector...

 

When I first plugged the tcase back in and started it up it was shifting into 4HI and 2HI perfectly but no 4LO. Tried to do the reset by pulling the fuse and waiting and nothing. Then tried pulling the battery for a few hours as well and nothing. Then tried to disconnect the encoder plug and when I plugged it back in the lights briefly came on and I shifted into 4HI. Then the lights went out and never came back on. Took a look at the encoder pins and nothing was corroded or bent. Have not got to the TCCM yet.

Just find it wierd that the lights went out and won't come back on no matter what I do. I've got an extra indicator switch on order so I can rule that out, but we all know its never that easy.

Like I said I work away from home all week, so on my list this weekend is:

Pull the encoder plug and check for the correct voltages
Check the TCCM pins
Replace the 4x4 switch to see if the lights will work
Go to junkyard and try to get the HVAC switch
Pin out the TCCM and see what I find

Any other ideas would be appreciated. Just remember I got no lights so I can't check for codes. In the encoder test process they talked about checking the ground path. Can anybody explain this "ground path"?

What I have done:
Replaced the vacuum switch on the tcase (was leaking)
Replaced the tcase/tranny seal (2qts overfilled)
Verified the actuator is working and holding vacuum
Tried to ground term 13 and get codes, nothing, no lights
Replaced leaking vacuum line at the canister

It has worked so I think I'm ok mechanically. Hate throwing money at stuff so I'm going to try and shoot it down but everytime I fix something I find 3 more things broke.

 

Dup post

 

All fixed. Transfer case seal, vacuum switch, 4x4 dash switch. Works like a champ. While at the junk yard I picked up a handful of encoders and TCCMs out of 233 cases if anyone needs one.