1994 Crown Vic A/C

Hi.
I just picked up a 94 Crown vic that has been sitting a while. The ac compressor is not turning on. Can I by pass the low pressure cut off switch to see if the compressor will run? Where is it located?
Then I want to check the pressure before having it serviced. I want to know what's going on before I have it charged..

Thanks,
John

I know that most compressors won't cycle on if they are low on refrigerant/oil.... You could go to like an advance auto and buy a dye in a can and add it to the system and it there is a leak you will see bright green. Then just fix the leak... it can be simple like an O-ring or condenser or it could get into really big money for repairs..

I would strongly recommond that after you run the dye test you have the system evacuated and recharged professionally... (of course after you have made any repairs) Its important to have the right amount of oil and refrigerant.

and has it been converted to 134a? because r11 is harder to come by and very expensive... before you get into all that you might really want to consider the condition of the vehicle...

good luck

Hi. Thanks for the reply.
The car is in very nice condition which is why I bought it. The a/c is already r134a so that's not a problem either.
I just want to do some troubleshooting before having a shop tell me that I need a bunch of stuff. I've evacuated systems before and recharged them, it's not that difficult do do. Unfortunately I don't have access to a vacuum pump any longer.
I also have a spare high mileage 94 that I can rob parts from, it's a/c works fine.

J

SOunds like your on the right track... I would run the dye test on your own and if the system is low on refrigerant that would be enough most likely to get it started...It worked in my Jeep ... and when the a/c was low it would not allow my secondary cooling fan to run... Good luck

Yes you can jump the low pressure switch to see if the compressor will engage. The switch is located on the accumulator.