AC compressor not working
 

As i keep finding electrical issues with this car that was stored for 2 years. I am to the AC. I find that the AC compressor is not turning on when you push in the AC button. Does someone have a schematic of the AC wiring or does anyone know where to check voltage for the compressor?

I'm not sure how to test but I know that the compressor will not engage if the freon level gets low - this is a safety mechenisim. There is a way to bypass the switch that is near the sight glass but which will temporarily turn on the compressor = but, someone else on the board will have to address that. You might check Search Results for "clarksgarage.com" too

GAKFU,
It took a minute to find you have a 88 944, you might want to upgrade your "User CP" on top. Edit your signature to let us know what you have.

anyway...

Tidybouy is correct. Your car is low on freon. To check if the compressor is getting voltage, there is a single wire that comes off the compressor. Unplug it about 2 feet along the frame and with the key ON-(not started) and the AC switch ON----the wire should have 12V tested with a Volt meter.

You could also jumper the safety switch ( a 3 inch wire with 2 female ends) mentioned above by the receiver/dryer for just a few seconds and see if the compressor kicks in.

Then read about converting from R12 to R134a:
http://www.the944.com/

GK
John

I metered a wire that goes to the compressor, first i had to clean the corrosion . With the key turned there is no voltage. I will try to jumper accross the switch.
Sorry about not posting the model year and make of the car. Brain fart after fighting this issue for hours.

No Voltage? Fuse? AC relay?

You could also run a loooooong 12V + wire from the battery + to the compressor (coil) wire (unhooked) and see if the coil energizes the clutch. Just ----tap----tap--------tap and listen for a click when the clutch engages. At least it will eliminate a bad compressor coil.

John

I jumper-ed across the pressure switch. Turned on the AC. The compressor engaged. I started recharging the AC. Eventually after charging the AC, when i reconnected the pressure switch the compressor would turn on.
But i have not been able to get the whole can of recharge to go into the system. And the AC is not cooling off the car.
Should i just keep trying until this can is gone?

OK, the compressor pumps.

What type of freon are you using??????

Did you add AC oil? Did you change the receiver/dryer?

Did you vacuum your system?

If not...

You will now have to vacuum the system for a total of 90 minutes.

After the first 30 minutes, stop. Wait 30 minutes to see if the vacuum holds, if not you have a leak to fix.

If no leaks, continue to vacuum for 1 hour longer. This is important to get out any moisture in the entire system.

Add freon and check your guages. If you cannot add freon now, your expansion valve may be blocked.

GL
John

Where do you hook the vaccum at. I'm guessing the highside coupler?

I did not add oil. The can of 134a contains oil sealer and leak detection. I also have not replaced reciever/dryer.