twinkiedooter

My 97 XJ 4.0 has a problem. Air hot or fresh/cold only comes out the defrost area and I cannot get it to come out onto the floor or into the cabin. Is there anything I am missing on how to get this selector to work? Heater works fine. No A/C at present. Damn near froze to death last winter. Any ideas?

SeriousOffroad

Vacuum leak.

Bustedback

There is a vacuum reservoir built into the battery tray and the hose that goes to it could have rotted off. There is also a black plastic vacuum line that runs along the right inner fender. It could be broken or battery acid might have eaten a hole in it. The cruise control and HVAC vacuum lines are supplied by that line.

twinkiedooter

Does anyone have a diagram of this hose so that I can follow it and fix it?

I do appreciate your info guys. Had I known this last winter I would have not froze when it got down to minus 10 in the daytime one day.

twinkiedooter

I figured out just where the elusive leak was when I compared engines with my neighbor's 96 and saw where the plastic vacuum line went into the firewall and bought a small hose to have installed that will hopefully fix my selector **** and allow me to have heat again

94zj318

I know on my '94 GC ZJ everything defaulted to defrost. I know on GC's when the plastic piece that opens the blend door (it opens and shuts when you turn the ****) breaks off, the door doesn't open and it defaults to the defrost vent, which is probably what happened to mine (I never investigated it since it was only a project vehicle). There's a fix for the blend door once you disassemble the dash.

Also, check to make sure no hoses in the HVAC system are disconnected, loose, or leaking... this can also make it default to defrost.

twinkiedooter

Thought I'd share this with you guys as I had NO heat last winter and damn near froze to death up here in Northern Ohio.

I noticed a very thin hose coming out of a 2" tit along the back of my engine compartment that looked like it was cut off. I could not figure out where it went.

My neighbor across the street has a 96 XJ and I asked him if I could look under his hood to see just WHERE this bad boy went. It went into the firewall just to the left of the a/c hose connections. I went to my mechanic and with the aid of two forecepts and some free tiny hose from Advance Auto (I buy all my stuff there and when I don't come in they send me postcards wondering where I went). And my mechanic hooked up the tiny hose and I cranked her on and USED THE SELECTOR DIAL AND HAD HEAT COMING OUT OF ALL THE VENT POSITIONS. OMG you have NO idea how happy I am to have heat again in my car. I bought it last fall and NEVER had heat all winter long.