Jeep Wrangler AC/Heat Problems
My air conditioner/heat only works when it's on high. It doesn't work on any of the other settings. I'd like to fix this myself, can anyone help me with this.
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It's likely that this has burned out and needs replacing.
Other less likely causes are a bad control switch, or issues with the wiring and connectors.
As the blower runs without blowing any fuses on 'high' it would appear to be ok.
You need to check the switch, wiring and connectors on the lower speed circuits. Check the appropriate fuses too.
The issue is with the diverter doors in the HVAC housing, which depending on the year may be manually controlled, or more likely operated by vacuum actuators.
If vacuum operated then the problem could either be a vacuum leak, faulty actuator(s), or a bad control switch (which controls both vacuum and electrics).
It's also possible that the doors are physically damaged, which was quite common on some years as the doors and linkages were made from a very brittle plastic.
Vacuum controlled in that case.
You can see the actuators move if you get your head into the footwells while someone operates the control knob.
If all the actuators work then the problem is damage to the doors or linkage inside the HVAC housing. Fairly big job to dismantle.
If some of the actuators work, then either some have failed or there's a problem with their vacuum feeds. Fairly easy to trace.
If none of them work, it's likely to be a major vacuum leak. Simple, start at the inlet manifold and follow the hoses until you find the leak.
When selecting floor level vents for heat, I notice only a little air coming out of the floor vents, with some air exiting at the defrost and demisters as well. Does not noticeably change when fan speed is increased. If panel or defrost vents are are selected there is noticeable strong air flow.
Does this sound like a floor door or actuator problem or is this normal operation.
Just had the upper fan box replaced to repair the bad mixing door. Dealer is now saying this air flow pattern is normal. I certainly does not feel normal when more air exits high when the floor vents are selected.
The vents are small compared to those on the dash, and unlike your face and hands, your feet and legs are usually covered.
However, if only the floor vents are selected then there should be little to no air coming from the face and screen vents.
With a little contortion you can watch the actuators move the doors as you operate the sliders on the HVAC control panel.
If an actuator functions but the door doesn't move, check the linkage between the two.
If the actuator doesn't function, look first for a vacuum leak.
Would appreciate professional opinion/advice.
Did you ever find a solution to your issue?
Thanks - Tom
Mary