A/C Compressor won't shutoff
Thread Starter
Intermediate
Joined: Mar 2006
Posts: 49
Likes: 2
From: Boston MA
A/C Compressor won't shutoff
My A/C compressor continues to run when the dial is in the off position on the controller on the console. It does shutoff when the dial is swicthed to heat, vent and defrost. The car is a '72 Coupe. Any suggestions?
72 Stinger
72 Stinger
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,113
From: Crossville TN
One of the little 'finger' contacts on the side of the heat/vent control head is not adjusted properly. Once you dig into the trans tunnel and pull that unit out (a PITA to do, unfortunately), you can make adjustments as needed to get the contacts to work as expected for each set position.
It is also possible that those contacts have 'welded' together...but unlikely. If so, separate them and use file or sandpaper to smooth them back to good condition.
It is also possible that those contacts have 'welded' together...but unlikely. If so, separate them and use file or sandpaper to smooth them back to good condition.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
I had this problem although my compressor was not hooked up the line to it was always hot. In my case it turned out to be the terminals to the anti dieseling relay (located behind the passenger dash) where corroded. After cleaning them it worked fine.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,113
From: Crossville TN
Interesting! Yes, the A/C clutch was engaged for a short time when the engine was turned 'OFF' so that the extra load on the engine would stop it. If that relay stuck 'open', that problem would occur.
P.S. You can take the top off that relay and clean those contacts. Much less expensive than buying a replacement. Put a bit of dielectric grease on those contacts if you repair it.
P.S. You can take the top off that relay and clean those contacts. Much less expensive than buying a replacement. Put a bit of dielectric grease on those contacts if you repair it.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Interesting! Yes, the A/C clutch was engaged for a short time when the engine was turned 'OFF' so that the extra load on the engine would stop it. If that relay stuck 'open', that problem would occur.
P.S. You can take the top off that relay and clean those contacts. Much less expensive than buying a replacement. Put a bit of dielectric grease on those contacts if you repair it.
P.S. You can take the top off that relay and clean those contacts. Much less expensive than buying a replacement. Put a bit of dielectric grease on those contacts if you repair it.
