2nd Gen Non-Engine/Transmission No 4wd , cruise and only defrost

[ERodgers]

Maybe I should preface this post. I recently took my truck to a dealer to have some routine maintaince done and got the truck back with this problem and some others ( SORE SUBJECT!). Anyway, I know all of these items worked before and the only place any work was done was under the hood. I did find one vacuum line undone, it came from the power steering pump and I hooked it up to a tee, sort of, located behind the motor. Not sure if thats the right place but the four wheel light came on - still no 4WD. I also notice that the tee located on the firewall had one line hooked up to the middle connection, one had a cap on it and the other one was totally open.



I know this is a common vacuum problem but without a total vacuum schematic for a 1997, which I can't find in my service manual, I'm not sure what hoses go where and if some of the Tee's are supposed to be blocked off or not?



Please help???????

 

[bmoeller]

Welcome to the TDR.



What did the dealer work on? There are vacuum hoses that engage the 4x4 and control the HVAC on the truck. There is vac. hose that runs to the cruise control servo (under the driver-side battery). The battery acid is prone to damaging/destroying the vac. hose and eating through the servo housing.

 

[Deezul1]

You are on the right track, prolly they knocked a vacum line loose. The default setting on the heat/ AC with no vacum is DEFROST. Look under the rubber strip that runs along the cowl to seal to the hood, there are several vacum connections there that get knocked off easily. There should be no lines laying loose or open so if you find one plug it in to the closest likely place.