Hey guys Ive been having a problem with my Cherokees heating system. Heat is very hot, blows out the vents perfect at idle etc but when I press the throttle down the air slows down from the vents and goes out to the floor and defrost. The further the throttle is down the less comes out the vents. I've checked all the vacuum lines in the engine bay but have yet to pull the climate control out. Would it be worthwhile to do that or do you think the problem may lay elsewhere? Thanks!

Andrew

 

Sounds like your controls are fine- check your vacuum canister for damage or disconnected lines.

 

Hey, I've owned 15 Cherokees and have had that problem on a couple of them. They both turned out to be a cracked vacuum line that goes under the battery toward the vacuum canister. The plastic vacuum hose runs along the fender and under the fuse and relay box. I would check it or just replace the entire vacuum line. Once you do that, it's all good. Hope this helps.

 

What year is your XJ? If it is 97 up it could be behind the glove compartment where the hub connects all the lines from the control unit. Check that and if not that then refer to what xfiles said. good luck

 

Just read you had a 96. Sometimes i get ahead of myself, still i would remove the glove box and check if there is a hub under there.

 

Hmmm... ???

There are a mirage of vac lines behind the heater control in the dash, Sure sounds like a leak.
Hook up a vacuum gauge and watch it has you increase the throttle maybe ??

 

Im gonna give that a try thanks for the quick replies guys I'll let you know what it turns out to be

 

I finally got around to looking into it now since it wasnt life threatening lol Very close to what you said, the black vacuum canister that the hose near the battery connects to had 2 holes in it the size of a quarter. I'm gonna get a new one but for now i just duck taped the hell out of it. Instant difference.