A/C Compressor cycling during non A/C operation.

Hi folks. I own a 92 XJ and the A/C system keeps cycling when I try to use the defrost setting on the HVAC controls. The aux fan kicks in as well. This becomes an issue during the winter months as we use the defrost almost exclusively during this time. It causes my XJ to over-cool. I know that I can simply disconnect the fan during the winter, but is this a standard setting for the XJ to operate the A/C compressor when using the defrost setting?

Yes this is normal. If it is "Over cooling" then you have

a.) a problem with your thermostat or

b.) you do not have the correct 195* one in there.


Alex

Ditto what ZombiE said. Many (if not all) new cars use the a/c during defrost to asist in removing moisture from the windscreen. Fog on the inside dissipates much faster when you blow dry air at it than it does when you blow moist air at it.

The thermostat should prevent over-cooling. Sounds like you need a thermostat.

Glad to know I'm not the only one with the AC kicking on at random times. I just assumed it was a short someplace under the dash.

Eagle said:

Ditto what ZombiE said. Many (if not all) new cars use the a/c during defrost to asist in removing moisture from the windscreen. Fog on the inside dissipates much faster when you blow dry air at it than it does when you blow moist air at it.

The thermostat should prevent over-cooling. Sounds like you need a thermostat.

Click to expand...

to add to that is to help keep the seals from drying up. i did a mod on my 2000 to keep it off in any setting till i want it on. i just have to rember to use it evry once an a while to keep it lubercated.

UPDATE: I changed out my thermostat today and discovered that the spring housing had broken off, causing the t-stat to bypass completely. This was the source of my overcooling issue