Andy69
Jun 23rd, 09, 10:56 AM
This is the ongoing search for the reason the compressor won't cycle on in my 69 GS400. I've posted this to V8Buicks, but this site has a lot more traffic. I might get one or two responses over there :(
I have a wiring diagram displayed below. It is different than the 69 Chevelle A/C.
The problem is I have no power to the compressor regardless of the position of the switch on the dash. Everything else works as it should - the fan speeds, switching between defrost, heater, and vent. The only problem seems to be that the compressor will not come on when the switch is placed in the A/C or recirculate positions.
I've got no power at the compressor with the A/C on. I've got power on the dash side of the red wire at two wire line connector in the lower left of the diagram, but not at the dark green wire, regardless of the position of the A/C switch. There does not seem to be a thermal switch anywhere like on the Chevelles. I guess they figured Buick owners have more money and can keep their cars in heated garages :) Since the problem apparently lies inside the car, and the blower works, I am assuming the A/C relay is fine.
I suspect the Compressor Clutch Control Switch might be bad, but I'm not sure how it works. I don't think it's a direct switch on the dash, but is probably a relay activated by the position of the blower and function selector switches. I already checked the fuses, but I will check those again JTBS, because I've been caught by that once before :) . I want to check every possible easy location before I try to replace or repair the CCCS, because removing it requires that I completely diassemble the dash (remove glove box and ductwork, remove dash pad, remove dash bezel - the dash bezel screws are covered by the dash pad, and the other stuff needs to come off to gain access to the dash pad screws)
Any ideas?
http://www.chevelles.com/showroom/data/500/medium/1970_AC_Wiring_Diagram.jpg
I have a wiring diagram displayed below. It is different than the 69 Chevelle A/C.
The problem is I have no power to the compressor regardless of the position of the switch on the dash. Everything else works as it should - the fan speeds, switching between defrost, heater, and vent. The only problem seems to be that the compressor will not come on when the switch is placed in the A/C or recirculate positions.
I've got no power at the compressor with the A/C on. I've got power on the dash side of the red wire at two wire line connector in the lower left of the diagram, but not at the dark green wire, regardless of the position of the A/C switch. There does not seem to be a thermal switch anywhere like on the Chevelles. I guess they figured Buick owners have more money and can keep their cars in heated garages :) Since the problem apparently lies inside the car, and the blower works, I am assuming the A/C relay is fine.
I suspect the Compressor Clutch Control Switch might be bad, but I'm not sure how it works. I don't think it's a direct switch on the dash, but is probably a relay activated by the position of the blower and function selector switches. I already checked the fuses, but I will check those again JTBS, because I've been caught by that once before :) . I want to check every possible easy location before I try to replace or repair the CCCS, because removing it requires that I completely diassemble the dash (remove glove box and ductwork, remove dash pad, remove dash bezel - the dash bezel screws are covered by the dash pad, and the other stuff needs to come off to gain access to the dash pad screws)
Any ideas?
http://www.chevelles.com/showroom/data/500/medium/1970_AC_Wiring_Diagram.jpg