Intermittent AC, 2001 OBW VDC

[william_hunter]

Hey all. I'm getting an intermittent AC problem in my OBW, and I am looking for other opinions..let me give you some background on this:

 

AC either runs from startup (ignition key starting car) or not at all. Sometimes, shutting the car off and restarting will start cold air blowing, sometimes it won't. I ran climate control diagnostics and checked the sensors according to this:

 

http://www.subaruoutback.org/forums/261742-post4.html

 

Step #1 resulted in a reading of 20, which apparently means no problems. The next step is to do temperature sensor readings. It was a hot day and the if I am reading this right, the first reading, outside air temp read at 94, second reading cabin air temp at 95, and third reading intake air temp at 54. Now this seems odd to me. I highly doubt the intake air was 54 degrees. That leads me to wonder: How can I check that intake temp sensor? I've also read that sometimes these are relay problems, and I wonder, how do I check that?

 

Any help is appreciated folks, thanks.

[eulogious]

Did the system complain about the air intake sensor? If the system said that everything is ok, then you probably just need a re-charge.

 

What are the pressures of the high and low side? I would check those first before going around and testing stuff that they system says is ok. If your pressures are good, then I would start looking into the electronics some more, but only after verifying that your system has enough refrigerant.

 

Until you get the pressures checked out, my guess is you are low on refrigerant.

[william_hunter]

The ac blows wonderfully cold when it works, so I don't know about that. I think that the temp sensor diagnostics just check whether or not they are sending a signal and the actual temp readings are what the system uses to determine need for routing the air through the AC condenser, since the whole system is controlled by the computerized climate control thingy.

[eulogious]

1st step in trouble shooting is eliminating what the problem is not. For a 2001 car it is not unreasonable to think that you might simply be low on refrigerant. Doing a quick check of the refrigerant pressure would tell us that everything should be ok, and then we can dig into it some more. Low refrigerant can do some funny things to AC systems...

Edited August 9, 2011 by eulogious