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gremlins with AC system

Posted: Fri May 01, 2009 2:06 pm
by wfoote
Picked up a 90 Legacy L wagon 5 speed. The compressor was shot it was replaced, I evacuated the system and recharged. Now for the weirdness.

I also resoldered the connector on the HVAC controller only to discover a broken defroster button. Got a serviceable unit from the pick n pull that fixed all the interior problems. Prior to changing the compressor with the new HVAC controller the pressure switch would not allow the compressor to run as designed.

The last problem is the compressor is on all the time. Even when the HVAC controller is turned off. I swapped out the four relays from a known good car with no change. The sub-fan is not on but it has been quite cool here. Is the sub-fan supposed to be running anytime the compressor is on?

Any suggestions?

Posted: Fri May 01, 2009 5:00 pm
by Legacy777
What year controller did you get from the junkyard?

There are some differences I believe.

Also, there are two different AC systems. Calsonic & Zexel. If components are mixed & matched, that may be causing some of your problems.

I have looked through the wiring diagrams for the AC system, and it can be kind of confusing. There is a sub-fan short connector that is located I believe just behind the passenger headlight. If that is shorted (connected) both fans should come on together and function the way things should. If you have AC, this connector should be shorted.

That may also be the cause of your problems.

Posted: Fri May 01, 2009 11:37 pm
by wfoote
I made sure it was a controller out of a 90 MY with the yellow connector. The car has a Calsonic system and that is what I replaced the defective compressor with.

Thanks, I will look into the connector and make sure it is shorted.

Posted: Wed May 13, 2009 1:34 am
by wfoote
Josh, do you have a location or picture of the shorting connector? I found what I think may be the connector, but the same connector on my other two cars is unplugged as well. (the ac works fine on those cars).

I also changed out all four relays and the AC relay under the dash with no change, the compressor still runs continuously even with the switch off.

Posted: Fri May 15, 2009 3:03 am
by Legacy777
This is probably the best I can do.
http://www.main.experiencetherave.com/s ... iagram.pdf

Look at connector F2

Posted: Fri May 15, 2009 4:05 am
by wfoote
Thanks, I'll look for that connector.

On the plus side, I figured out why the compressor was always on. The PO decided to ground a wire coming from the thermistor that sensed the evaporator coil temp.