Worked fine last fall; this summer...no cold air! compressor does not appear to click in when AC turned on in cab.

Even though compressor does not operate, can it still just be low on Freon? Can I try to add w/o compressor running? Any suggestions?

Thanks,

Jim

 

With my limited understanding of automotive A/C, yes, it can just be low on freon. There's a pressure switch in the system, and when the pressure falls too low, the switch causes the compressor clutch to disengage.

As for adding with the compressor off, I cannot say with absolute certainty, but, yes, you should still be able to add freon. (Logic: Otherwise, how else can the system brought up? At some point, any new system will need freon, and won't have enough pressure to engage the switch. So surely some freon can be added without the compressor running, in order to bring the pressure up high enough to trip the switch and get it running. The other possibility would be to shunt or bypass the switch in order to get the compressor running, but I suspect that could be harmful to the compressor.)

I have an 02 Impala whose A/C I'm trying to fix this week, and I'm expecting the same situation. I put a new evaporator in it and a new orifice tube, and now I need to pull a vacuum on it, then charge it, and I know the compressor won't be running initially.

That said, I picked up a couple books at the library on automotive A/C, and plan to do a bit of reading before I connect the freon, just in case

Doug

.

 

You might consider doing it right - take it to a shop and have it evacuated, leak tested, and recharged. Should cost you about 60 bucks labor plus freon.