A/C Defrost Only
Thread Starter
Newbie
Joined: Jun 2011
Posts: 23
Likes: 1
From: Phoenix, AZ
Year: 1989
Model: Cherokee
Engine: 4.0 L 6 CYL
After getting my A/C fixed. I now have this problem. It will only blow out of the defroster. As of now I know that it could be a vacuum problem but I have yet to find a rotted or damaged hose. Is their a specific fuse for this? It is getting up to 110
here!!!

here!!!
Junior Member
Joined: Feb 2010
Posts: 45
Likes: 0
From: blanchard,ok
Year: 1994
Model: Cherokee
Engine: 4.0
If I recall there is a vac line under the hood by ther blower motor that controls weather or not it goes out the vents and if its broken it will only work on defrost might check it out and hope it helps .
CF Veteran
Joined: Jun 2011
Posts: 1,845
Likes: 3
From: S.E. Tx
Year: 1992
Model: Cherokee
Engine: 4.0 I6 firepower ignition, cat-back w/ magnaflow muffler, poweraid tb spacer, optima blue top
It can be a vacuum hose, most likely it is. But it could also be a little door in the dash that turns to direct the air or there's an actuator under the dash.
Thread Starter
Newbie
Joined: Jun 2011
Posts: 23
Likes: 1
From: Phoenix, AZ
Year: 1989
Model: Cherokee
Engine: 4.0 L 6 CYL
I've been looking! I can't find this HOSE!~~! working on it is brutal in the heat.!!!!! Does anyone have a picture of this hose. I am not a jeep expert but can easily replace a hose. as for the dash thing I took the dash apart the other day to fix my radio and I think I saw that A/c actuator if it is round and gold in color???
Thread Starter
Newbie
Joined: Jun 2011
Posts: 23
Likes: 1
From: Phoenix, AZ
Year: 1989
Model: Cherokee
Engine: 4.0 L 6 CYL
yes! thank god I got this problem fixed. so rewarding. ha. ok here is how i cracked this code. at least as i see it.
I searched for vacuum diagrams relating to A/C components and came across this

and then this

i started by following the line shown in the first pick, it was taped to another line, I turned my wheel to give me more clearance. I followed it up from point 4 to 6 -5 -3 and then I noticed a connector, I disconnected it and decided the only way to find this was to blow into the hose to determine if any leaks were there. I heard a noise and instantly followed the hose to feel the leak or leaks. I found it and only one was present and to my astonishment a tiny hole was present right after the bend in 3, I immediately fixed it up and my A/C is blowing through the VENTS !!!! it is awesome FULL BLOWN COLD A$$ A/C
I searched for vacuum diagrams relating to A/C components and came across this

and then this

i started by following the line shown in the first pick, it was taped to another line, I turned my wheel to give me more clearance. I followed it up from point 4 to 6 -5 -3 and then I noticed a connector, I disconnected it and decided the only way to find this was to blow into the hose to determine if any leaks were there. I heard a noise and instantly followed the hose to feel the leak or leaks. I found it and only one was present and to my astonishment a tiny hole was present right after the bend in 3, I immediately fixed it up and my A/C is blowing through the VENTS !!!! it is awesome FULL BLOWN COLD A$$ A/C
Seasoned Member
Joined: Sep 2010
Posts: 289
Likes: 0
From: Juneau, AK
Year: 1998
Model: Cherokee
Engine: 4.0
yes! thank god I got this problem fixed. so rewarding. ha. ok here is how i cracked this code. at least as i see it.
I searched for vacuum diagrams relating to A/C components and came across this

and then this

i started by following the line shown in the first pick, it was taped to another line, I turned my wheel to give me more clearance. I followed it up from point 4 to 6 -5 -3 and then I noticed a connector, I disconnected it and decided the only way to find this was to blow into the hose to determine if any leaks were there. I heard a noise and instantly followed the hose to feel the leak or leaks. I found it and only one was present and to my astonishment a tiny hole was present right after the bend in 3, I immediately fixed it up and my A/C is blowing through the VENTS !!!! it is awesome FULL BLOWN COLD A$$ A/C
I searched for vacuum diagrams relating to A/C components and came across this

and then this

i started by following the line shown in the first pick, it was taped to another line, I turned my wheel to give me more clearance. I followed it up from point 4 to 6 -5 -3 and then I noticed a connector, I disconnected it and decided the only way to find this was to blow into the hose to determine if any leaks were there. I heard a noise and instantly followed the hose to feel the leak or leaks. I found it and only one was present and to my astonishment a tiny hole was present right after the bend in 3, I immediately fixed it up and my A/C is blowing through the VENTS !!!! it is awesome FULL BLOWN COLD A$$ A/C
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Senior Member
Joined: Oct 2010
Posts: 842
Likes: 4
From: Everett, WA
Year: 1996
Model: Grand Cherokee
Engine: 5.2L
Senior Member
Joined: Oct 2010
Posts: 842
Likes: 4
From: Everett, WA
Year: 1996
Model: Grand Cherokee
Engine: 5.2L
Seasoned Member
Joined: Sep 2010
Posts: 289
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From: Juneau, AK
Year: 1998
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Apr 2009
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Year: 2015, 2012
Model: Grand Cherokee (WK2)
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There is also a gaggle of plastic vacuum lines coming off the interior climate control selector, but these are pretty protected. But one could slip off the manifold.
Most of the time it is a pinhole in a vacuum line or lines under the hood. Pay particular attention to the hard plastic lines around and going through the firewall on the passenger side. They could have a kink or be rubbed through in one area.
The oval-shaped vacuum canister seems to be pretty tough. I don't think they crack all that often, but sometimes a fitting can break off.
Blowing to the windshield is the default mode. Vacuum is required to actuate and hold the blend door to the cabin/dash vent mode.
Most of the time it is a pinhole in a vacuum line or lines under the hood. Pay particular attention to the hard plastic lines around and going through the firewall on the passenger side. They could have a kink or be rubbed through in one area.
The oval-shaped vacuum canister seems to be pretty tough. I don't think they crack all that often, but sometimes a fitting can break off.
Blowing to the windshield is the default mode. Vacuum is required to actuate and hold the blend door to the cabin/dash vent mode.
Seasoned Member
Joined: Jun 2011
Posts: 276
Likes: 1
From: Washington
Year: 2000
Model: Cherokee
Engine: 4.0
Thank you Sir. I'll keep all this in mind once I decide to tear into it on a sunny day. Considering its still raining here I don't really need A/C haha. Thanks Again


