911 Air Con

We have a 1988 911 with a faulty AC.
Does anyone know what the high and low pressures at the compressor should be with the engine running.

Pressures on the A/C system is relevant to the load on the evaporator coil and outside temp. If your A/C is not working, check to see if the clutch is engaged when you turn the temp switch on. If it cycles on and off, the system is low on refrigerant. Your system is probably a R-12 system which means you probably will have to have a certified A/C tech to work on in.

If the compressor is not short cycling, then check the discharge temp - again, you need to have a load going across the coil - it should be about 40F.

If the coil freezes up, then it is most likely low on refrigerant. Again, when this happens, the unit will run for long periods of time and the air flow will become reduced. Ice accumulates on the coil and blocks the air flow.

I hope this info will help you in troubleshooting your A/C problem.

Regards

Steve K.

I converted my 1988 911 from R-12 to R-134a. It was not difficult. I have the freon capacities and the oil capacities if you need them.