Jeep AC with a mind of it's own

[Skip]

It's an 03 Jeep liberty Renegade. The AC works and blows cold, but it doesn't stay on the front vents. It moves around mostly between the defroster and the floor without anything being touched. Any ideas?

 

[fuelfather]

bad trap door between the ducts, or bad control head.

 

[zembonez]

Sounds like a blend door issue. No doubt it is electrically controlled on that vehicle.

Who needs AC in Texas?

 

[Dredge]

I have a 2000 Wrangler that did similar.....only it would decide to change to the floor and not blow cold air. I fixed it by replacing a few things (meaning everything that was a quick plug in) and it started working again. Then the rest of the Jeep started breaking down....it's a Jeep thing.

 

[Dcav]

Door actuator problem, fairly rare on the Liberty, very common on the Rams, could be a control head as well.

 

[LJH]

Door actuator problem, fairly rare on the Liberty, very common on the Rams, could be a control head as well.

I have the same thing going on the wj now, looks to be the actuator.

 

[Dcav]

I have the same thing going on the wj now, looks to be the actuator.

Is it knocking in the dash area? Or the doors acting funny, knocking noises are a giveaway for a actuator problem. Doors not opening or closing properly could be another issue.

 

[Skip]

Thanks guys, some things to research.

 

[Kyle]

No trying to jack the thread.. My 96 cougar A/C will randomly cut off.. I found a spot on the dash (when I was angry one day) that I can punch and it turns back on immediatly... Bad switch in the control unit?

 

[fuelfather]

Bad ground, or loose connection somewhere.

 

[Willy]

The air conditioner is pneumatically controlled. A loose air hose or connection near your control knob will cause the air flow to default to defrost. Look for a loose hose between the engine and the air control knob.

 

[TexMex247]

Older generations of vehicles utilize engine vacuum to actuate blend doors and other functions. You probably have a vauum diagram on your emissions label under the hood. It will map out a vacuum source that leads to the a/c if it uses vacuum. Usually they wind up at the firewall near the area where the A/C plumbing enters your dash. The defrost position is the default setting of vacuum operated systems. Willy is on the right track...unless it uses electric servos, not sure on that YM. Kyle, it sounds like your blower motor is shutting off and not your a/c. Does the A/c button stay illuminated ? That would indicate that the compressor is still operating but the blower fan might have a problem. It is also common for a bad blower resistor to make intermittent contact which will "shut off" airflow by stopping the blower motor. Which makes sense if you are hitting the right underside of your dash to make the A/c work. Most systems bypass the blower motor on the highest setting. Does your a/c cut-off even when the blower is set to full speed ?

 

[Kyle]

.......Kyle, it sounds like your blower motor is shutting off and not your a/c. Does the A/c button stay illuminated ? That would indicate that the compressor is still operating but the blower fan might have a problem. It is also common for a bad blower resistor to make intermittent contact which will "shut off" airflow by stopping the blower motor. Which makes sense if you are hitting the right underside of your dash to make the A/c work. Most systems bypass the blower motor on the highest setting. Does your a/c cut-off even when the blower is set to full speed ?

No buttons or lights to go by in the cougar, just selector knobs and temperature settings. However, when it does cut out, I typically just turn it off and I can hear what sounds like the a/c decompressing (like normal) even though the blower is not working. I didn't mention that it is thermostatically controlled.

As far as where I pucnh my dash. There is a cushioned divider perfectly between my a/c control unit and the passenger side air bag, all the shock from the punch rattles the control unit and it kicks back on, which makes me think it is a switch.. I know nothing about them so I am just guessing... (I did that with my girlfriend in the car and it made me feel like the Fonz...)

But yes, you are right, my blower motor is shutting off. Not my ac like I originally stated.