From: Wally Plumley [wplumley@bellsouth.net]
Sent: Wednesday, October 03, 2001 12:00 AM
To: 928
Subject: [928] Re: no AC compressor turn on

At 11:35 PM 10/2/01, DIAMONDDOT wrote:
>OK, I TAKE MY CAR INTO THE LOCAL PORCHE DEALER FOR TIMING BELT SERVICE.  I
>ALSO HAVE A REAR WHEEL BEARING REPLACED.  AFTER PAYING $1900 FOR ALLOF THE
>WORK TO BE DONE I DROVE OFF.   I DIDN"T DRIVE CAR FOR A COUPLE OF DAYS.
>     tHEN I TRIED THE AC.  THE COMPRESSOR DOESN'T COME ON?  I TOOK IT BACK TO
>THE DEALER AND HE SAID HE ONLY REMOVED ONE WIRE AND SHOWED ME THAT IT WAS
>BACK ON.  I ASSURED HIM THAT IT WORKED WHEN IT WENT IN.  HE THEN TOOK OUT A
>JUMPER OF SOME SORT AND TOUCHED IT DOWN IN FRONT OF THE RADIATOR NEAR THE
>RIGHT HEADLAMP.  THE COMPRESSOR TURNED ON.  HE THEN TOLD ME THAT THAT TELLS
>HIM THAT I AM LOW ON FREON?  DOES THIS MAKE ANY SENSE TO ANY OF YOU?  I JUST
>LEFT AND TOLD HIM THAT I HAD TO GET BACK TO WORK.  I JUST WISHED I WOULD HAD
>FELT THE AIR IN THE CAR WHEN HE JUMPED IT TO SEE IF IT WAS COLD OR NOT.
>SORRY SO LONG---ANY SUGGESTIONS?
>
>RON CONNELLY
>1984S 50K NEW TIMING BELT,WATER PUMP, BUT NO AC




The dealer gave you the easy answer, which may even be correct. What he did 
was to jumper 12 vdc to the freon pressure switch located on the 
receiver/dryer. If the freon gets low, this switch opens to save the 
compressor. By jumpering here, he directly activated the A/C compressor clutch.

First check is to kneel down and pull the connector from the pressure 
switch on the receiver/dryer. Turn the ignition switch ON, turn the A/C ON, 
and check for 12 vdc on the terminals in the wire harness. If you have 12 
vdc on one, put a jumper between the terminals, and you should hear the A/C 
compressor clutch click. If you remove the jumper and plug the harness back 
on, and the compressor doesn't click, you are low on freon, and the dealer 
probably didn't have anything to do with it.

If you don't have 12 vdc on either of the terminal in the pressure switch 
connector, the next check is to pull the black plastic shield at the back 
of the engine compartment, and find the A/C anti-freeze switch. This is a 
small block near the center of the car with two electrical wires. Turn the 
ignition ON, turn the A/C ON, and test for 12 vdc on each of the electrical 
terminals on the switch. If you have no power on either terminal, the 
problem is in the fuse or the A/C controller. If you have power on both, 
the wire is disconnected between the anti-freeze switch and the pressure 
switch.

Wally Plumley
928 Specialists