A/C Problems

[justakid]

I have a 94 SHO ATX with a zillion miles on it. My A/C has recently quit working....at all. I have checked the pressure on both the high and low side...and they are the same...120psi. I know this has something to do with the compressor but I'm not sure what to check by way of electrical and other components of the system. Any help would be appreciated.

Thanks,
Wes

 

[projectSHO89]

Wes,

Just been there, done that!

The same pressure indicates that the compressor is not turning. On my 89, I could see the clutch hub engaging and spinning and it looked like it was turning the compressor, but the inside of the clutch was shot and the compressor shaft was not turning. If I had gotten in there with an inspection mirror and a flash light I would have seen that the center shaft was stationary (20/20 hindsight, you know).

I ended up replacing the whole compressor and clutch assembly because I didn't feel like risking a new clutch on a 14 year old compressor of dubious condition.

A reman 10P15F with clutch was $250 from PartsAmerica.

Steve

 

[bigdaddy]

First thing is to make sure you have 12v going to the clutch.Could be a defective low pressure switch.The switch is screwed into the side of the reciever/dryer(by the battery). With the ignition on(not running)jumper the electrical connector to the switch,the clutch should click in.I would start there.Just rebuilt my entire system on my 92.I'm a ASE Master tech with over 35yrs automotive experience.I have a bone to pick with some forum members,(not you)about ASE mechanics.Please contact me and will chat.Good luck with your AC problem.Let me know.

 

[naval-avi8or]

I've got a 94 with a gazzilane miles as well. My huntch is you need a new a/c clutch and coil. To troubleshoot do the following. Take a multi meter and check for 12vdc on one side of the cycling switch connector with the car running and a/c on max. If yes take a paper clip jump the connector with with the paper clip. Did the comperssor kick on. If yes bad cycling switch if no take data panel over radiator off locate the relay control modual (black box). Test the second wire from the front on the bottom row for 12vdc. If yes check the fouth wire from the front on the lower side for 12vdc or you can check it at the a/c coil connector.If you did't have power to the second wire on the bottom row than wither your paper clip isn't making contact or if you plugged it bake into the cycling switch for the test then the cycling switch is bad. If you get 12vdc to the second wire but not the forth wire the relay module is bad.

First test the a/c coil connection for 12vdc with the a/c on max. (one trick to try prior to disconnecting the connector is to use a broom handle and tap the clutch and see if you can get it to engage). If you can get it to engage or you have power to the a/c coil connector then its time for a new a/c clutch and coil.

Just had to do my 94 last friday.