Installed new AC compressor...connector does not match
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 48
Likes: 2
From: Lakeland TN
Installed new AC compressor...connector does not match
New Denso AC compressor in 89. AC clutch wiring connector does not match. I do not have a problem using old connector if I know the color code. Wires are both black on the new compressor. Do I need to be concerned with polarity? I referenced GM service manual and color code in manual does not match my car. AC compressor was never replaced until today. Thanks in advance for any assistance. Kevin
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
I'm currently runing a used low mileage compressor off a '90 on my '89 with no issues.There are 2 different style connectors/plugs for the Denso units most '90 and up units have the smaller "2" pin version without a diode. I've read some claims about there being a diode installed on/within connector on the early C4s but mine ('89) had none for whatever reason. How do I know?...I cut the old connector off the car's side of the wiring harness and checked it - then installed the newer "2 pin" weather pack style connector and hooked it all back up. Works great.
CF member "Oldmanalsaksa" is correct for the most part. It doesn't really matter about the polarity - it is a rat race any way - the circuit loops through the clutch's coil - coil takes the electrical "load".
If CF member "RWDsmoke" blew the diode and fuse on his the circuit or coil must have been "shorted" in some way.
CF member "Oldmanalsaksa" is correct for the most part. It doesn't really matter about the polarity - it is a rat race any way - the circuit loops through the clutch's coil - coil takes the electrical "load".
If CF member "RWDsmoke" blew the diode and fuse on his the circuit or coil must have been "shorted" in some way.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
An electro-magnetic clutche need a diode or one way circuit device as without it, the electrical surge created when it disengages will fry controls. Through '91, it was in the Connector under a small black tab. After that, it was integral with the Coil.
'89 wiring depends on Controls, but assuming you have Electronic, it's hot from the a/c fuse and grounded at the Blower Module. The locking weatherpak (assuming the connector matches what it had and regardless of wire color) usually assures that's it correct (though I've removed the tab to confirm it). If the connector doesn't match, they sold you the wrong one (and I've spent more than a few minutes at Parts Stores insisting they go and get the right one). If you want to try and live with that, than the diode needs to flow back towards the hot lead, but I'd guess that if it doesn't have one, it's integral. I've never tried to deal with that.
'89 wiring depends on Controls, but assuming you have Electronic, it's hot from the a/c fuse and grounded at the Blower Module. The locking weatherpak (assuming the connector matches what it had and regardless of wire color) usually assures that's it correct (though I've removed the tab to confirm it). If the connector doesn't match, they sold you the wrong one (and I've spent more than a few minutes at Parts Stores insisting they go and get the right one). If you want to try and live with that, than the diode needs to flow back towards the hot lead, but I'd guess that if it doesn't have one, it's integral. I've never tried to deal with that.
