The A/C on my '07 seems to have failed sometime over the winter. It's blowing ambient air temp unfortunately. The pressures are equal to ambient temp when it's off so I think it have a decent charge, However when I turn the A/C the low side is high (~45-50 PSI at 70 degrees) and the high side is low (~75-80 psi). I think it's probably either the expansion valve stuck open or the compressor is failing (the clutch does engage and the fan turns on). Should I just replace both since I have to evacuate the system anyway? Also would others recommend a new condenser as a preventive measure?

Thanks.

 

Pressure level of static system does not indicate charge level, only that enough charge is present to have liquid refrigerant. If compressor is short cycling (rapid on/off) a low charge is likely. If compressor runs continuously then agree w/ your assessment.

good luck

 

Thanks TexasHonda that's helpful. The AC compressor doesn't cycle, when you turn it on it doesn't cycle off on it's own, just stays running until you manually shut off AC. I tested again today, this time with a little help, and at 70 degrees ambient temp I got about 60 PSI on low side and 85 PSI on high side at idle with AC on full. At 2000 RPM the low side dropped to about 10 PSI and the high side went up to 100 PSI. Now I'm thinking perhaps it is just a low charge. Does that sound a little more reasonable or am I still at my original thought of the expansion valve and/or AC compressor?

 

I would think you would get some cooling w/ those pressures. If yes, then low charge is likely. A can of R134a is cheap diagnostic.

good luck