Been troubleshooting ac on my Dad's truck. Read the FAQ and after going through all the diagnostics on the ac (low pressure switch, high pressure switch, ac clutch relay, coil resistance all OK) I found issue with clutch gap. I removed the washer in the clutch and put everything back together and the clutch is engaging properly now (gap is around .020 now) and seems to be working ok. I borrowed a set of gauges from a friend and want to verify the low and high side readings to see if the charge is adequate. Getting about 48F air out of the vents with outside temps around 85F. Could someone give me an idea of what the low and high side pressures should be running at that outside temperature?

Thanks for the help and the nice HVAC FAQs.

 

Thanks.

I'd guess that low side would be around 32-40 psi and the high side around 190-240.

 

Thanks, that gives me an idea on what to expect when I check it.

 

Thanks again, pressures were a low. I charged it to 35psi low and high was running 215psi. 43F air out of the center vent. Dad is happy.

 

That's ridiculously good results.