A/C coming through defrost vents
#1
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Year: 1993
Model: Cherokee
Engine: 4.0L I6
A/C coming through defrost vents
First off, I've searched the forums for an answer and have not found one. OK, I have a 1993 XJ Sport 4x4 and the a/c is coming through the defrost vents. Now if I put it on heat it will come through whatever vents I have selected, but when I move the temp selector to cold it stops coming through the selected vent and starts coming out the defrost. I've checked the vacuum lines and they all seem intact. Any help would be appreciated.
#2
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
When the temp selector is moved to the right, heat should come out whichever vent position is selected. The defrost position engages the compressor regardless of where the temp selector is.
Last edited by djb383; 03-13-2012 at 07:01 PM.
#3
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OK, I understand about the compressor kicking on, but why won't the vent selector work while the A/C is on. No matter which vent is selected it just blows out the defrost. Its starting to warm up here in central Texas.
#4
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Year: 1993
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Could have a vacuum leak around the vacuum reservoir ball. I believe the spring returns the system to defroster when no vacuum pressure is present. The A/C compressor kicking on might cause the small amount of vacuum it accumulated to disappear. Just a thought
#5
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Year: 1993
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Another thought would be possibly the blend door got ahold of a vacuum line and pinched it, hence why it works on hot. I'd take the box apart and have a look
#7
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Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
check line that runs beside battery next to fender going to vacuum ball behind front bumper common spot also lines coming out of firewall pass side by blower motor
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#8
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Year: 1993
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Thanks guys, fixed it. It was the gray vacuum tube coming out the back of the heater control valve. It had come off some how and was just hanging there out of site. I'm glad that is all it was.
#10
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Year: 1999
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Hey man I'm having the same problem with my 99 Cherokee. I've looked under the hood quite a bit and I can't see any hoses that have come loose. I know you posted this 2 years ago, but could you post a pic of which hose was loose on yours? Much appreciated.
#11
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Year: 1990
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#13
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Year: 1999
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So the vacuum line is intact and connected. I checked the pressure and it read low so I refilled it with 134 but the air still blows through the defrost vents. My neighbor seems to think the feed to the dash vents has fallen off. Can anybody confirm or deny this?
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