'93 500 SEL air conditioning woes

I'm still having trouble with my air condtioning.

I started off with leaks and have replaced the evaporator core. The car does not lose coolant now.

I am having problems with the compressor turning off and on intermittently. I have replaced the sensors in the evaporator core and the one behind the insturment cluster. This did not help. I have not replaced the pressure sensor on the drier (I think it was there I'm going on memory.) I get a code for a bad sensor, but when you run the sensors on a scope they do not show anything wrong. One thing I did find is that if you disconnect the mono valve (or more correctly on this one the duo valve) the compressor starts working within 30 seconds. Leaving that disconected will not keep the compressor running.

Can anyone help with this?

[stevebfl]

The compressor is controlled by the Base Module. It watches for compressor speed versus engine speed among other things.

The V8 compressor wiring is strung so tight that when the motor mounts sag it takes out the connection on the compressor. Look at that connection.

Thanks a lot! That worked. The mounts show some signs of wear, but they are not too bad. I ended up splicing 2" of wire into the wire that powers the compressor. This prevented the connection from failing. The air works fine now. By the way, do you know where I can get some R12? My '91 Previa needs some work also.

[Arthur Dalton]

Originally posted by stevebfl
The compressor is controlled by the Base Module. It watches for compressor speed versus engine speed among other things.

The V8 compressor wiring is strung so tight that when the motor mounts sag it takes out the connection on the compressor. Look at that connection.

Now, WHERE in the WORLD, I ask you all.... are you going to get diagnosis like that at a click of your key-board... Didn't even have to pick up the phone.........
This site is PRICELESS !!!!!!!