Air Cond. question

[DJK555]

1988 GMC K2500 5.7L There is a pressure switch near the firewall that has a cap with two wires. Once removed it exposes the connector and also a set screw between the connectors. Can anyone help with an adjustment procedure that can be done without a pressure gauge. I'm trying to reduce the time the compressor cycles. Thanks in advance.
David

 

[Texas Jim]

1988 GMC K2500 5.7L There is a pressure switch near the firewall that has a cap with two wires. Once removed it exposes the connector and also a set screw between the connectors. Can anyone help with an adjustment procedure that can be done without a pressure gauge. I'm trying to reduce the time the compressor cycles. Thanks in advance.
David

David,
If the compressor comes on and just stays on a very short time and then cycles off and stays off for a fairly long time... it is most likely just a tad low on freon.

 

[Zembonez]

The pressure switch ensures that the AC cycles properly when it is filled with the right amount of freon. It's what makes the system operate efficiently. I don't think there is any way to adjust this.

 

[Draenor]

1988 GMC K2500 5.7L There is a pressure switch near the firewall that has a cap with two wires. Once removed it exposes the connector and also a set screw between the connectors. Can anyone help with an adjustment procedure that can be done without a pressure gauge. I'm trying to reduce the time the compressor cycles. Thanks in advance.
David

David,
If the compressor comes on and just stays on a very short time and then cycles off and stays off for a fairly long time... it is most likely just a tad low on freon.

The pressure switch ensures that the AC cycles properly when it is filled with the right amount of freon. It's what makes the system operate efficiently. I don't think there is any way to adjust this.

Correct. You cannot adjust the pressure at which it comes on and off. As the 1St Jim stated, it is just a tad low on refrigerant, which is why it is not cycling correctly.