A.c stuck on defrost
Newbie
Joined: Jun 2010
Posts: 7
Likes: 0
From: Minneapolis, Minnesota
Year: 2000
Model: Cherokee
Engine: 4.0L 242 I6
Exactly what Cruiser said-
Look inside your front bumper for a small disconnected hose. Plug it back into the cannister.
Fixed mine in 10 seconds.
Look inside your front bumper for a small disconnected hose. Plug it back into the cannister.
Fixed mine in 10 seconds.
CF Veteran
Joined: Jan 2009
Posts: 1,964
Likes: 6
From: Baltimore, Maryland
Year: 1994 1993
Model: Cherokee
Engine: 4.0
The way Jeeps work is..If there is any break in the vacuum system that controls the heat/cooling etc it goes to the defrost only as the default setting. So somewhere along the line between the vacuum ball and the heat/ac control switches there is a break in the tubing. Just trace everything and eventually you'll find the break. Just as an example I had to take my battery out to work on something and when I reinstalled it the battery nicked the tubing running along the fender and that was all it took to make my heat blow out the defrost only
Last edited by Programbo; Jun 29, 2014 at 05:32 AM.
Newbie
Joined: Jun 2010
Posts: 7
Likes: 0
From: Minneapolis, Minnesota
Year: 2000
Model: Cherokee
Engine: 4.0L 242 I6
look underneath/inside your front bumper first- that's the most common place a disconnect occurs. If the little hose is connected to the vacuum reservoir, then the problem is deeper and more difficult to reach. If it's not connected, you've found your problem, without a wrench or screwdriver...
Trending Topics
I have the same issue. AC is stuck on defrost.
I pulled out and replaced the switches and it didn’t fix it. I have no holes in the hose at all. (I smoke tested it). I changed the AC actuator and noticed that motor works for the heat/cool switch. I can’t figure out the problem.
Is there a motor similar that works the middle switches for defrost and AC? Maybe that motor is bad? I can’t figure it out. Any help would be great. Thanks
I pulled out and replaced the switches and it didn’t fix it. I have no holes in the hose at all. (I smoke tested it). I changed the AC actuator and noticed that motor works for the heat/cool switch. I can’t figure out the problem.
Is there a motor similar that works the middle switches for defrost and AC? Maybe that motor is bad? I can’t figure it out. Any help would be great. Thanks
Seasoned Member
Joined: Sep 2019
Posts: 328
Likes: 94
From: Around the world
Year: 2001 / 1999
Model: Cherokee (XJ)
Engine: Fire breathing 4 point Oh!!!
CF Veteran




Joined: Jul 2012
Posts: 3,134
Likes: 360
From: Andover, VT
Year: 1999
Model: Cherokee (XJ)
Engine: 4.0 L
Get a vacuum pump and test the system to ensure you do not have a vacuum leak before throwing any more parts at it. 99% chance you have a vacuum leak, or a check valve is bad somewhere. I had a check valve that was bad that took me forever to find. When removed I could only blow through it in one direction (like one would expect) but when pulling a vacuum it would not hold nearly as much vacuum as it should have.
CF Veteran


Joined: Nov 2017
Posts: 2,478
Likes: 275
From: Southern Texas (former AZ & Aus)
Year: 1999
Model: Cherokee(XJ)
Engine: I6 4.0L
Ya'll can slap me if I'm wrong for mentioning it....but stating that this is stuck "on".... can it only be a vacuum issue? Or is it possible that compressor clutch could be stuck on instead or in addition to the defrost issue?
Thread
Thread Starter
Forum
Replies
Last Post
eagle11401
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
7
Oct 8, 2015 04:36 PM
LittleRed94
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
5
Oct 6, 2015 08:09 PM
BluJay
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
Sep 23, 2015 11:22 AM
BNJeepsta
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
2
Sep 18, 2015 06:04 AM
shotseven
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
0
Sep 6, 2015 03:06 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)



