A/C Intermittent (Warm and Muggy)
 

Hi guys,

My AC recently started acting up and only working intermittently. It generally blows freezing air for the first bit of driving and then the air becomes warm and muggy for a while (~10-20 minutes). It then becomes cold again and repeats the cycle randomly. I checked the freon level and that was good. Also since it is working part of the time that means the compressor should be good, correct? Any ideas?

Also, a potentially unrelated problem I'm having is that very hot air blows on the driver's right foot (from the vent I believe) whenever the windows are open. Is this normal?

Thanks!
Matt

How did u check the freon level? Were there a dipstick or a sight glass?

I'm in for answers on this. My AC was doing the same thing before it died altogether. I have all the parts for a complete overhaul, but I'd really like to know why the hell it was acting like that for future reference.

I used one of the guages from the autoparts store that came with a recharge kit my roommate purchased. I know next to nothing about AC systems so please let me know if this is not right.

After a significant amount of googling and searching I finally came across this. I think it may be relevant.
http://www.jeepforum.com/forum/f11/a...83/index2.html

So I took it all apart, removed a washer, and put it all back together and the clutch plate no longer spins at all. Anyone have any ideas? Would it be easiest to just bite the bullet and get a whole new compressor?

I have no idea what vehicle this is or what year it is, but if it's an XJ, the hot/cold cycling is normal during periods of high humidity where ice will form on the fins of the evaporator. The low pressure cycling switch will open and close causing the PCM to turn the compressor clutch on and off. This regulates the refrigerant system pressure and controls the evaporator temperature. Controlling the evaporator temperature prevents condensate water on the evaporator fins from freezing and obstructing air conditioning system airflow.


The low pressure switch is supposed to prevent ice from forming but it may be too sluggish to keep up in high humidity conditions.