i was told i would prob get better responces over here, so here i go
ok guys (and gals) i know i have been asking a lot of questions, but hey, thats what we are all here for, right? well, i found out why the 4wd does NOT work on my truck. yeah, you guessed it, the vacuum hose. when you take your hand and squeeze that thing the hose goes into and then goes to the diff, the 4wd light comes on and works. but there is NO suction what so ever in that vacuum hose. traced the hose back, goes into the t-case. the hose appears to be fine. is there anything i should look for?

 

to add, when we put the stick into 4wd, hi or low, the light on the floor does NOT light up. the front driveshaft DOES spin. we put it on jacks a few days ago, noticed the spinning driveshaft, but no 4wd. but if i squeeze that thing the 4wd lights light up and the front tires do spin....help

 

you mean where the stick is there is a light? damm another thing I have to fix.

 

I dunno but would could install a posi-lok. With that installed correctly, you can toy around in 2Lo. (RWD only)

 

well, got it working tonight. all we did was just took off the vacuum line (for now) and pulled the piece back that makes the front diff "lock" and put some small hose clamps on it . sure, the 4wd icon on my truck is lit up 100% of the time now, but just not the t-case. so i have 4wd again . we will be welding the rear up soon and then getting her muddy!!!!!!!

 

The hose on the t-case should have come off of a three way vacuum switch. There is a techincal bulletin at the dealer about this switch failing and causing the heater/air conditioning controls to malfunction. The switch fails and sucks fluid up into the controls through the vacuum lines. But yours may have failed on the line to the 4-hi/2-hi vacuum ball under the battery box....replacing the switch may restore 4x4 functioning to your vehicle.

GM has remanufactured this switch to reduce the failures associated with the switch. I think there is a post on this site about it....if not then there is one on the s-10crewcab site.