You can look at the wiring diagram in one of the d/ls from WCCC it will show that the blower and compressor are 2 different circuits. The compressor should get full voltage in all positions of the switch and won’t get any when the switch is off. The stepper side of the switch is a ground that comes off the resistor after the blower motor. If you got the same stepped voltage going to the compressor from 2 different switches you tried, then it must be in the wiring. Odds are both the switches you tried aren’t bad.
Well, I charged the system up and turned it and on after tightening one fitting that was loose on the bottom of the dryer (checked with dye) the system is working fine…I’ve got 48 degrees out the center vent on high blower speed. I still have to start it on high blower speed to get the compressor clutch to engage, but once going works on all blower speeds until the off position. Current draw on high is 1.7 amps and 1.2 on medium and 0.5 on low. The radiator fan never drops it’s speed…???
After review of the wiring diagram for the clutch and the blower fan it looks like some one has hacked the wiring. The clutch must be currently connected to the Black-Yellow strip wire that runs to the blower motor. It should be connected to the green wire that routes through the A/C thermostat switch and the Clutch Control switch, turning to a black wire coming off the clutch control switch, then going to the clutch.
Thanks, all that’s good as far as the wiring goes. The system is all charged up now with 48 degree air coming out of the vents with ambient temperature of 72 degrees. Even though the amp draw declines going through the blower speeds nothing opens up electrically with the compressor or the radiator fans until the blower switch is set to off. Electrical mystery!
I just looked at the original owner’s manual to this 68 Cougar that was given to the first buyer of this vehicle in June of 1968 and sold as a dealer demo, and in the instructions for the air conditioner to start the system at max cooling and the blower in the high position. There must have been a reason for that.
Here is a picture of the page in the original owner’s manual that instructs the owner to start the AC on high blower speed.