Need Help on A/C
 

Hi guys, I need help again. This time is my A/C. I purged the system and put a few cans of R-12 in. I turn the switch on and it does not run. There is no power to the low pressure cut off switch. If I bypass that switch and power the compressor directly, the system runs and blows cold as it should. I am a novice on Porsche and any help will be greatly appreciated as always. Thanks.

what year is it? And by power the compressor, I assume you mean 12 volts from the battery straight to the compressor?

"Purge the system"----does this mean vacuum?
"few cans or R-12"----2 should be more than enough
"no power to low pressure switch"----no power required-it is a pressure switch.
Jumper the switch-plug the compressor back in and the compressor will kick in with the engine running and the AC switch on.

This is as much as I know.....

GL
John_AZ

It is a 1984 944 N.A. Yes 12 volts straight from the battery.

Hi John,
Yes 2 cans of 12oz R-12 and one 4oz can of oil, yes vacuumed. I mean the low pressure cut off switch on the dryer, I thought it should be powered and cuts power off when the system is low on freon? I am still thinking about your advise to keep the car here and ship a Cuda to Europe. I will put it to the best shape possible, keep it here for a year and if it passes the test I will ship it. You guessed it, I am a stubborn guy. Thanks again for all the Good Help. George.

A/C amplifier probably has a burnt trace, or at least that's what happened to mine with the exact same symptoms. Something shorted to ground. The amplifier is under the passenger side kick panel, above and to the right of the glove box. It's black in color and about the sizes of an index card, or 3x5 by 1 inch deep. Open up the case and check the traces on the back of the board. The black/white wire should have 12v out of the amplifier.

24oz of R12 should allow the pressure switch to engage the clutch on the compressor, although you need 40.6 oz of R12 for a full charge.

My best guess is that the front seal on the compressor blew out and shorted to the clutch to ground, that's what happened to me anyway.

Thanks a lot. I will let you know what I will find out. George.