IMG_2079.zip IMG_2080.zip IMG_2075 - Copy.zip on my 96 the vacuum line comes off the 4wd actuator and goes to the transfer case but it has a split that goes up to a wired plug that seems to go around the back of the engine and plugs into the wiring for the brakes. the switch that divides the vacuum hose and the wiring-what is that switch called so I can replace it! Thanks I tried adding some photos. Hopefully they can be opened/seen!

 

I can't open your pic. but if its the same unit as the pic. the older post about it - its not a switch its a sensor - I never did find it new or much info about it - I replaced it with a bone yard part and from what I could find about it maybe a vacuum sensor for the TCCM

 

I was not able to open the picture either! Here are two links at Amazon that might be the part you are looking for.
L

 

1st one is the switch that goes on the transfer case - 2nd is the light switch thats mounted in the front axle. Neither are in the vacuum line its self.

 

Found it Part # 88880029. It is a kit you have to buy. Reached out to AC DELCO directly and they found the old part # and was able to trace it to the new number or the kit number. Thanks for the help and suggestions! Here is a link to the part on Amazon:

https://smile.amazon.com/ACDelco-888...3&sr=8-1-fkmr0

 

kool thanks for letting us know - way diff than what i could ever find about it .....

 

Yeah no problem. Glad I tracked it down. Crazy how the old part number doesn’t lead to this kit. I suggested that to AC DELCO.

 

https://smile.amazon.com/ACDelco-888...3&sr=8-1-fkmr0
Good morning; I looked at the kit above on Amazon you had mentioned the back of the engine. Where do you install this kit? Glad you got it fixed.
L

 

The vacuum line is the one that splits off the 4wd actuator vacuum line that goes to the 3 way switch on the top of the transfer case. Once you split the vacuum line it goes up with the line included to the vacuum switch included. The area where this happens is around the inner fender area right around where the radiator overflow bottle is attached. The electrical line then plugs into the switch and then wraps around the backside of the engine and then plugs into the two different plugs, one going to the braking system and the other going to the switch that is plugged into the front differential which that switch is located where the actuator cable is plugged in-FYI. Hope this explains it good enough.

 

The only info I could find on it was it was a sensor for the tccm but as it wires to the abs system it must also change the way the abs acts - maybe disabling the abs part of the front brakes while in 4WD
My old sensor wouldn't hold vacuum
With my MORF I couldn't get the 4WD to engauge until I swapped out that bad sensor .....