[for3300]

The PO didn't have AC in my 83 chevy silverado. I am trying to get it going. The problem is I dont have any power to the dark green wire going at the 2 prong connector for the compressor. I checked the fuse and it looks good. I am trying to see if you guys can help me track down the problem. I have downloaded a wiring diagram and looked at the Haynes manual and cant seem to find that particular wire. Please help it hot here in OK

[pepi]

Some late model compressors will not come on if the freon is very low. Will need to jump a low pressure switch to make it run so that the freon can be added . Very common and is noted in the service manual.

[for3300]

Before I saw the last person posted a comment I had tried to add more refrigerant and the compressor didn't come on/no power to the dark green wire connected to the compressor. I followed the dark green wire and it goes from the compressor to a 2 prong connector by the firewall to a connector at the accumulator. Can you guys tell me where the low pressure switch is located. Is it the 2 prong connector at the accumulator?

[75gmck25]

The round two prong connector on the sensor in the evaporator line is the low pressure switch. You can bypass the switch by pulling the plug off the switch and putting a jumper between the two sockets in the plug.

There is also another switch as part of the temperature probe, which is inserted into the fins of the evaporator. It should be mounted on the side of the black housing, near the blower motor. This sensor is designed to cut the compressor off if the temperature in the housing is lower than 35 degrees. That keeps the compressor from coming on in freezing weather.

Bruce

[LATECH]

Originally Posted by for3300

Before I saw the last person posted a comment I had tried to add more refrigerant and the compressor didn't come on/no power to the dark green wire connected to the compressor. I followed the dark green wire and it goes from the compressor to a 2 prong connector by the firewall to a connector at the accumulator. Can you guys tell me where the low pressure switch is located. Is it the 2 prong connector at the accumulator?

Yes The low pressure switch is at the accumulator it has the the 2 prong connector on it.The dark green goes to the compressor and the light green goes to the selector in the dash. Check for power on the light green wire with the key on and the hvac switch in the a c position.If it is dead the check fuse marked Ignition 3. check it with the key on use a test light. If the light lights on both side of the spades then there is an open circuit. Next stop would be at the a c switch. Does not appear there is any other thermal fuse or thermoststic switch in the system according to the EWD.