94 CAMRY Air Conditoner question

[bandag]

Hi all, have not been on here for a while, (that's because my corolla has been running good!) I just bought a 94 Camry that has been setting for 2 years. It runs good but when I press the A/C button the green light comes on but I do not hear the compressor run, and of course there is no cold air coming out of the vents. Someone said that if the freon is low that the compressor won't run. Can anyone tell me if that is true? If not what should I check first before assuming that the compressor is bad? Thanks for your help!

[Zembonez]

Sounds like it is low (or out of) freon. Time to pull a vacuum on the system and check it for leaks. May just be an O ring seeping.

[BMR]

Yes, there's a low pressure switch on the suction side of the compressor. If the charge is really low, it won't let the compressor start (keeps the compressor from destroying itself). If it's a little low, the compressor will start, but after the compressor runs a bit, it'll pull the pressure down on the suction side to where it kicks off. It'll sit there and cycle on/off repeatedly.

To find it, follow the freon line going from the condensor (the smaller radiator-lookin' thing in front) to the compressor. You're looking for a switch with a couple wires coming out of it. Pull the connector off and install a jumper on the connector. If the compressor still won't run, something else is wrong. WARNING: Don't run the compressor for more than a few seconds that way.

[Stillrunning]

Don't do the jumper on the pressure switch until you've tested for proper pressure. The system is probably almost empty and over 2 years there could be moisture in the system. Safest is to pull vacuum then recharge and test for leaks.

[bandag]

Thanks guys, I will try as you instructed and let you know how I made out.