tfossum Posted November 20, 2014 Share Posted November 20, 2014 I have a 2005 Legacy GT Ltd and I'm running into an issue with the AC. Several weeks ago my AC started to fail, functioning only intermittently. Gauges showed system had pressure but the compressor wasn't engaging. Compressor was receiving good voltage, therefore concluded the compressor clutch had gone bad. Research suggested this wasn't too uncommon, and I replaced the clutch in lieu of swapping from a salvaged compressor. I also replaced the expansion valve. Pulled vacuum on the system for an hour, checked and it held vacuum. I charged the system, which was a little bit guess work because the ambient air temp was right about 30*F (I know I know, but we're going to Florida next week for Thanksgiving). Compressor worked, AC got cold. I thought everything was fine, but a little concerned that maybe the system was overcharged (though, based on the label in the car I shouldn't have been based on the volume I added). Today I drive to lunch and it's about 55*F out and the AC is working, but cycling more than I'm accustomed to (car cabin was getting warm in the sun). But it WAS working. I drive home after lunch and can't get the AC to blow cold. Also can't hear the compressor engaging. Get home I check the pressures Low/High are 70/50 respectively (weird, but the compressor isn't running). The compressor is now NOT receiving any volts though the fuse is good. Evacuated/Charged the system again thinking maybe as it warmed it went into over-pressurized zone, am now sitting 40/40 and still the compressor won't get volts. Hints? It's certainly warm enough inside the cabin to trigger the climate control to turn on the AC - is there a way to test this? Link to comment Share on other sites More sharing options...
GTEASER Posted November 20, 2014 Share Posted November 20, 2014 Did you replace the dryer when you did the expansion valve? Also, you can unplug the connector from the pressure switch (on 2000-2004 Legacys the switch is screwed into the dryer) and jump the appropriate pins with a wire. This will trick the clutch into engaging to test the compressor and confirm the proper functioning of the switch. GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
tfossum Posted November 20, 2014 Author Share Posted November 20, 2014 Yes, replaced the drier. The low pressure switch has four connections, and I'm accustomed to seeing two. Hints there? Link to comment Share on other sites More sharing options...
GTEASER Posted November 20, 2014 Share Posted November 20, 2014 Yes, I remember that. Do you have a wiring diagram? I can't remember off-hand which two need to be jumped. GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
JmP6889928 Posted November 20, 2014 Share Posted November 20, 2014 My thought would be pressure switch too. Link to comment Share on other sites More sharing options...
travrach Posted November 20, 2014 Share Posted November 20, 2014 What are you using to measure weight? A scale? 40/40 is low, I've seen them sit at 40/40 and a machine pulls out only .30 I think you need to verify how much you have in it before jumping the switch, just because it turns on after jumping does not verify you have correct amount to even trip the switch. http://legacygt.com/forums/picture.php?albumid=2095&pictureid=10014 Link to comment Share on other sites More sharing options...
tfossum Posted November 20, 2014 Author Share Posted November 20, 2014 Maybe I wasn't clear about the sequence. Last night I put about a full 12oz can in plus a little from a prior can, which I'm guessing put me in 13 - 15oz range on the label in the engine compartment (if I recall correctly). Today I couldn't effectively fill it because the compressor would not engage, resulting in 40/40. Link to comment Share on other sites More sharing options...
GTEASER Posted November 20, 2014 Share Posted November 20, 2014 My 2003 needed 18-23. GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
tfossum Posted November 20, 2014 Author Share Posted November 20, 2014 Thanks for the ideas. Seems it was the AC control relay. Swapped the sub fan relay for the AC relay and got consistent performance. Was then able to fully charge the system again. Then, swapped the relays and again experienced intermittent performance. Swapped again and it worked consistently. Link to comment Share on other sites More sharing options...
YeuEmMaiMai Posted November 21, 2014 Share Posted November 21, 2014 first off you got to draw the system down next add exactly what Subaru recommends test system Guessing with the cans is a BAD idea, no way to accurately measure the charge on the system. Over charge = compressor cycles on and off rapidly Link to comment Share on other sites More sharing options...
xtea Posted November 21, 2014 Share Posted November 21, 2014 The relay on these guys was poorly designed. Get new one and you should be good. Link to comment Share on other sites More sharing options...
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