Subaru Problems? Ask a Mechanic for Answers ASAP
This car has common problems with the AC compressor clutch revolution sensor.
So, when you turn the off with the AC on, the next time you start the car, how do you get the AC to work again? Do you have to shut it off with the (now non-working) AC off and then back on again and then turn the AC on and it works?
Have you tried changing the AC clutch relay yet?
Relay A on this diagram. It's in the under hood fuse box.
I'm sorry, what do you mean about the fan?
The relay that I circled in blue controls the activation of the AC compressor clutch. It does not control the blower or the cooling fans.
The level of the coolant should not affect the AC operation---unless it's low enough to make the engine overheat, which would cut the compressor operation off.
You could test it with a multi-meter. You would need to measure resistance across the terminals while powering or grounding the other two pins. Not really very practical.
It's best to just replace it.
The next step would be to test the pressure switch. Here is the schematic. If you have a two pin sensor you can jumper the pins with a paperclip and the compressor should kick on. If you have a four pin sensor then jump the pins across. This should make the compressor run as well.
If jumping the connector pins doesn't run the compressor then the problem is somewhere in the compressor or compressor clutch. If it does make the compressor run then your problem is likely in the pressure switch. You'll have to evacuate the system to change the switch.
Yes, make sure the engine is running with the AC switch on. Jump 1-2 and it should run the compressor. No, it won't shock you-DC voltage can't overcome the resistance of your body unless it is up around 10,000 volts or more.
Once you plugged the connector back in it came on?
I think that pressure switch is defective.
Which cap are you referring to? The radiator cap? The antifreeze coolant and radiator have nothing to do with the air conditioning. Removing or replacing the radiator cap will have no affect on the function of the AC compressor.
Ok, so we're on the same page. I just got lost for a minute there. If you plugged the switch connector (the cap) back in and the compressor came on then I would definitely suspect a bad pressure switch.
You could change the switch on your own, but you would need to evacuate the AC system first and then re-charge it after.
You will need an AC evacuation machine to safely remove all of the refrigerant. One like this:
At some point you should inject the system with a luminescent dye to try to pinpoint that leak. You could do it before you evacuate it, but you would need to run the AC system for a little while to see where the dye leaks out. That might be easier with the system working correctly, which requires replacement of the pressure switch.
The pressure switch is the part that the connector that we were trying to jump with the paperclip plugs into. That switch tells the Compressor that there is enough refrigerant to turn on- since refrigerant acts as a lubricant for the compressor. Running without lubricant would be a bad idea.