AC compressor clutch relay location please?

OLDGUYMECHANIC65

MEMBER
1997 CHEVROLET SILVERADO
5.7L
V8
2WD
AUTOMATIC
265,000 MILES

My A/C compressor turns on and blows cold only when the relay is jumped. I tested the relay for resistance and jumped wires connected. I can hear it clicking on the inside of the relay. A/C works but the relay must be jumped in order for the compressor to kick on. I tried swapping the relay with other relays in the under hood fuse box with same thing happening. All wiring looks to be in good condition. No power is getting to low pressure switch. I am a mechanic but this has me extremely puzzled. What do think is going on? Thanks ahead of time.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi:
That is an interesting one. If you feel the relay click, then it's getting power. If you jump it and the compressor works, then we know the circuit is good. The only thing that makes sense is the relay isn't making a connection on the relay box. Are the pins good and not corroded? Check to make sure none of them are loose and pushing in when you install the relay.

I attached a pic below showing the compressor relay. Is this the one you are referring to?

Here is a link explaining how to test a relay. See if it working properly.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Let me know.
Joe

Image (Click to make bigger)