blinkbears

Got an 88 XJ. When I set it to AC or vent, the air blows out of the appropriate places, floor, vent, and defrost. Fan blows just fine from hi to low. But when I put it on the heat setting I only get air blowing to the floor and a little to the defrost. Not from the vents. I'm guessing that this is vacuum related? The lines form the vacuum ball in the bumper looks good, I couldn't find any broken or anything. Is it possible that when I was installing my cd player that I knocked something loose or broke something behind the HVAC controls that would cause this problem? Just tryin to get some input before I go tearing the dash apart again. That CD player was a biatch to get in there.

Thanks everyone.

blinkbears

Or maybe it's supposed to be like that? Anyone else Heat setting work the same way?

olmiaakc

will your system eventually work if you leave it on the desired setting or is the problem constant?i had the same problem after moving the vacuum "ball" to underhood after installing my winch.but it would eventually work after about 30 seconds(maybe after building vacuum?)i left the stock vacuum lines alone.a few weeks later i shortened the lines and eliminated a lot of the rubber hose.my hvac vents etc. worked perfectly after that.sounds like a vacuum problem.i also installed a cd player but do not remember a whole lot of hvac components back there.good luck.

TerBeau

did you remove that thing behind your front bumer? if so it will do that. happend to me so i put it back in and fixed my issue. i pulled mine out when i cut my bumper and fenders. now its ziptied back in with all hoses put back on.

blinkbears

I did not remove the vacuum ball. The problem seems constant because I took it for a short ride today and it didn't start working properly. Reason I asked about me possibly breaking behind the unit something installing my cd player is cuz the headunit I put in has alot of extra rca outputs and this metal box (honestly, not sure what its function is) attached to it so it was a chore finding a place to stuff everything so that I could put the darn thing in.

Nope, pretty sure it's been in the same place for the past 23 years.

____

I'm just wondering if maybe this isn't really a problem at all and the HEAT setting is just supposed to work this way. Because if I select the VENT setting, it works properly and air blows out the vents. If I select the DEFROST setting, it works like it's supposed to. Can someone confirm whether or not when the HEAT setting is selected that air is supposed to blow to the floor and to the windshield? Give me some peace of mind lol. Thanks.

jwilson2598

Sounds like normal operation for an 88. My Comache was the exact same way, and so are the other 96 and back era XJ's I've been in.

blinkbears

Perfect. That's what I was lookin for. I feel better now it seems like it's normal. THank you.