Hello All,

sifting through all the A/C threads, I have yet to see a clear explanation of how to manually turn on the A/C compressor. I suspect it’s low on r134a since one day it stopped working then the next day it came back on magically. Then last week it died for good. As far as I know if there isn’t enough 134a then the compressor won’t engage so I can’t even refill it. Any help is appreciated.

 

Forcing the compressor on is not part of the charging procedure. You should troubleshoot and fix the problem before attempting to recharge the system. The low side needs to get to at least 32.1 psi or higher before the compressor will operate. If you can't build that much pressure with your refill then you have a pretty decent leak. You risk further damaging the hvac system if you don't fix the leak as you will be losing lubricant, and moisture from the atmosphere will intrude into the system. If you do have enough pressure on the low side but the compressor will not operate then it could be an issue with the a/c clutch or the high side is over pressurized.

 

thanks! I did do some minor troubleshooting with the fuses and relays. I will check the pressure on the system.