I no longer have heat or AC coming from the panel vents and the shift on the fly 4 wheel drive no longer works. I have determined that I do not have vacuum pressure going to the vacuum relay thing above the hub on the passenger side. When I run a vacuum line to the relay from my jeep and turn the switch to 4x4, the vacuum relay swiches over to the other line (has a re and a black) so I believe it is working fine. I think the problem is that I do not have a vacuum source working. Neither the red or black have any vacuum at all when the truck is running. I have no idea if I have a leak or what the problem could be. Someone please help!!!!

 

Did U check fuse for vaccum pump for starters and if pump is working

 

Where is the vacuum pump? The thing I checked I believe is some sort of relay that relays the direction of the vacuum (is it a pump). I checked all the small fuses and they were all good. I didn't see a fuse that said anything about vacuum pump.

 

Does anyone know the source of the vacuum?

 

Vacuum pump motor is on the top of the right/passenger side inner fender, just behind the reservoir..

 

That is supposed to supply vacuum? The thing with the red and black hose? I thought that was some sort of relay. When I ran vacuum to it (another source) and turned the 4x4 switch the vacuum was relayed out the other port.