I bought a 2004 WRX recently. Montana weather got hot enough to where I wanted to use the A/C. Well guess what? It didn't turn on. That is, the compressor doesn't come on and the RPMs don't increase by 500. Plus I hear nothing "kick in" and the blowing air never got colder.
I tested the power at the in-cab fuse box; it was good. I tested the power at the power connector on top of the compressor; nothing. I replaced the relay in the under-the-hood fuse box. It was only 10 bucks and I wanted to make sure that it wasn't the cause. Still no compressor turning on and no power at the contact.
I know some (most?) cars' A/C systems have a cut-off switch somewhere on the A/C line that switches the power off if the pressure is too low. Does anyone know where that switch is or how to test it?
I hooked my tactrix cable up and used Enginuity 0.4.1 (www.romraider.com) logger and checked all 4 of the A/C options. I did it at idle. Here are those results:
Air Conditioning Switch: Remained at zero entire time
Air-Con Compressor Signal: Remained at zero entire time
Air-Con Mid Pressure Switch: Remained at zero entire time
Air-Con Lock Signal: Remained at zero entire time
I repeatedly turned the blower on with A/C on and off with temp set to the coldest level. I'm guessing the lock signal would have read 1 if what I believe about the pressure being too low is true.
Can anyone give me some further ideas? I don't think the compressor is dead, at least I really hope it isn't since they are ~$300 new.
Also, in Enginuity logger, is battery voltage of 12.24v bad when the engine is off and the ignition is on? While idling it was 14.08.