1992 240 A/c not working

gorph512 · Post by **gorph512** » 06 Jul 2009, 14:39

My son's car had r-12 just converted it over to 134a.

Here is the problem a/c compressor will not come on. dissconnected wire going to compressor and ran jumper wire to pos. of battery, it works. Plug it back in and not working. The front fan to the condenser is also not working. Was able to charge system with compressor jumper to battery and running water over condenser. I have no wiring diagrams on this car. Oh and does anyone know where the a/c high side service ports is located.

pbrodersen · Post by **pbrodersen** » 21 Jul 2009, 19:53

The low-pressure cutoff switch may be bad. It is usually on the accumulator. It serves to turn off the compressor in case the charge becomes too low, to prevent compressor damage. Another possibility would be the ac relay going bad.

The high side port may be on the rear of the compressor itself. I have also read that some years did not have one. My '87 744 has it on the compressor, near the high side line (marked "D" for discharge).