Dash AC works, blows cold but compressor drains battery when not on.

[TXheat]

Just like title says, saw a whisp of smoke once when connecting it back, so I either keep the compressor disconnected or starter battery drains, any chance it's a stuck relay, can I test the relay using a 9 volt battery? Could it be the compressor is going bad? thanks for any help.

 

[Aa1ssradio]

Sounds like the clutch is staying engaged. Have to troubleshoot it back to relay possibly. Check for voltage at clutch when it supposed to be off

 

[Bigblockyeti]

If the relay contacts are welded, a 9V battery will tell you nothing, you need to do a continuity test. If the relay checks out, you need to systematically troubleshoot everything upstream to find out what is calling for an engaged clutch.

 

[TXheat]

If the relay contacts are welded, a 9V battery will tell you nothing, you need to do a continuity test. If the relay checks out, you need to systematically troubleshoot everything upstream to find out what is calling for an engaged clutch.

Ok. I need to do a continuity test on the relay? If the relay pulls out and it's not welded than it can be tested with a 9 volt? So it could be a stuck compressor clutch? Thanks

 

[TXheat]

Sounds like the clutch is staying engaged. Have to troubleshoot it back to relay possibly. Check for voltage at clutch when it supposed to be off

Do I put my meter on the connectors of the compressor to test? Thanks

 

[Kevin D Pem]

The relays are cheap and most of the time enerchangeable. simply swap out one of the other known good relays with the ac relay.

 

[Aa1ssradio]

Ok. I need to do a continuity test on the relay? If the relay pulls out and it's not welded than it can be tested with a 9 volt? So it could be a stuck compressor clutch? Thanks

Compressor clutches normally don't stick. There is voltage applied to it somehow that is keeping it engaged. Put negative end of meter on ground and start tracing the hot wire back off the clutch.

 

[TXheat]

The relays are cheap and most of the time enerchangeable. simply swap out one of the other known good relays with the ac relay.

Didn't know you could that, thanks