AaronS

Two door 1992 4wd Jeep Cherokee 6cyl 4.0l

When i turned on the heat there was a loud and fast clicking noise. It sounded like a plastic gear having its teeth ground off or like a broken plastic chunk being slapped around by a pump impeller or like a bad fan bearing clicking as it rotate (hard for me to say). This noise was emanating from the passenger foot well.
When i turned off the heat the noise slowed down and stopped. When i turned the heat back on the noise came back and as it increased in speed it suddenly stopped. Unfortunately, hot air also stopped coming out of the air vents. Instead all the hot air, which was still blowing from the heater core, was coming out in the passenger foot well.

When I move the manual air control from Heat to Vent, or any of the three AC setting, air flows out of all the dash vents like normal. The defrost setting also works fine. So putting the air to hot and using any of those settings warms me up just fine. Its only when i put it on the heat setting that there is no air flow from the vents.
I have noticed that on all the setting no air comes out by my feet where i know on heat air used to blow at my feet. So now my feet are always cold.

I would love to get to the bottom of this but after taking the dash panels off I realized just how little i know... In fact i know so little about this problem that google searching hasn't turned up anything, i suppose its because i don't know what to search for.

My guess is that its some kind of air door control motor gear that ground itself apart or a damper door i cant see that inst opening. but I cant seem to find anything related to those on my 1992 jeep.

any help would be greatly appreciated. Sorry for being long winded.

Cane

if I understand your post correctly, it's normal and heat is only supposed to come out from the foot area.

if you want hot air coming out of the vents, just put the switch all the way to the hot side and use the vent setting.

AaronS

I think its a missunderstanding, its definetly not normal for the heat to come out only in the passanger footwell let me add that its not coming out of a vent but rather blowing out anywhere it can escape under the dash as if a door to the vent tubes (if one exists) did not open to let the hot air flow and instead the air is forcing its way out anywhere it can.

Thanks for responding with something though! Any and all thoughts are welcome!

CCKen

Has your XJ ever had the HVAC Unit removed or has the floor console ever been removed.


There's a chance that the air duct that goes through the floor console to the outlet in the back of the floor console has come loose from the floor outlet at the HVAC Unit.

AaronS

Neither have ever been removed but the hose having come disconnected would make sense though it doesnt explain the noise i heard before it stopped working.

Bluchrg45

[QUOTE=AaronS;3197215]Two door 1992 4wd Jeep Cherokee 6cyl 4.0l

My 1999 jeep needed a diaphram. First it was switch, then it was core then the vents stopped working, then they did just with wrong identifier. AC sent heat out, heat came out defroster, defroster came out when middle vent switch on. Now I need a diaphram. Too tough a job and very expensive. I'll keep my jerry-rigged system