AC compressor not switching on

[Sixt8Chrgr]

My AC has been working great this Summer and today the compressor would not engage. With the blue 12 volt feed wire unplugged from the compressor I have 12 volts. Plug it into the compressor and the voltage drops to 0. Is my compressor shorted to ground now? I know nothing about how the compressor works.
Any ideas? Thanks guys.

Lawrence

[70 sublime]

Still have gas pressure in the system ??

[Sixt8Chrgr]

I need to double confirm, but like I said it was blowing very cold one day and the next the compressor would not come on. If the pressure was low I believe I would see 12 volts on the compressor side of the plug once plugged to the 12 volt power source.

[cdr]

I need to double confirm, but like I said it was blowing very cold one day and the next the compressor would not come on. If the pressure was low I believe I would see 12 volts on the compressor side of the plug once plugged to the 12 volt power source.

plug the compressor in, check for power on both sides of the pressure switch located on the drier.

[John_Kunkel]

If you have 12V at the compressor, the switch is closed but the switch might have an internal fault that drops the voltage under load. Jumper around the switch to see if it's faulty.

If jumpering around the switch gets the system working OK, the pressure is OK.

[Sixt8Chrgr]

Ok thanks guys. Anyone happen to have a picture of the pressure switch? If not I can look it up in the FSM.

[John_Kunkel]

It's mounted on the receiver/drier.

[Bronzedodge]

Not in all years - some factory systems actually did not have a pressure switch 69 and earlier.  Retrofit kits usually did.

[Sixt8Chrgr]

My car is an early 69 and does not have a pressure switch.

Last night I was playing with the car and the compressor came back on. It was late and I did not check the voltage at the compressor plug while connected to the feed. Will check and confirm 12 volts or another voltage.

Thanks