So I've been having a problem with my 95 XJ. The heat and AC aren't blowing correctly. There's 3 options for the heat, vent - heat - defrost. The only one it blows on is when I put it on vent. And when its on vent, it won't blow if I have the gas pedal down. Like if I'm driving down the highway, there will be no air flow coming into the cab. If I take my foot off the gas pedal, it will start blowing air. Then if I put it back on the gas, it will stop blowing. When I have it set to heat, it barely blows at all even with the blower on high. The blower seems to be working fine cause it's loud and you can hear it blowing air. What could be my problem? Is there a door broken somewhere in the vents or somthing like that?

 

Your vacuum reservoir ball and/or check valve is broken or missing? Those dampers and the hot water valve are vacuum operated. You don't have engine vacuum while accelerating and without the check valve and reservoir there's none in reserve.

 

Will you explane with a little more detail? Where's the check valve? Where's the vaccume resisvore ball? I don't know anything about heat or AC, so I don't understand.

 

The vacuum source ( on a '94 ) comes off of the rear part of the intake manifold, to run the heat/AC climate controls, cruise, etc. There is a little disc-shaped check valve just above the fitting in the manifold. The vacuum line runs from there, across the firewall, and on the right side of the fire wall it has a tee and another little check valve, and a line from that runs inside of the cabin.
The major vacuum line continues on along aorund the corner, and along the right inner fender well, and down to behind the front bumper, where the vacuum reservoir ( a plastic tank ) is located.

My approach would be to start at the source, at the top/rear of the intake, and follow the vac line & look for broken fittings, hose sections etc, on down to the reservoir area. Reservoir is ahead of the rubber splash panel on the right front wheel well...

have fun !

 

This:

 

Oh dear, my front bumper is smashed on the passenger side, that's probably my problem lol. I'll look into it. Thanks for your help guys.

 

If you find it crushed you can find another ball at the JY for pretty cheap..doesn't even have to be one from am xj...

 

Yes. Call your local junkyard and ask the guy who answers the phone if he has any *****.

 

Absolutely. .but make sure you tell you want small ones..you can't fit the big ones...

 

Here it is, the resivore is probably broken. But yeah I'll get one from a junk yard or ebay, it's getting cold and I need the heat working right. Especially for the defrost.