Couple of questions on AC in a 68
Got a 68 6 cyl which had factory AC. New aftermarket compressor and condenser. Uses all the original controls which I restored 6 years ago. At that time it worked like expected but never got as cold as I think it should. I even put on a fan shroud which it never had but that didn't make much difference.
I'm back playing with it again and the AC was still behaving just like it always had. I bought one of those Arctic Air cans of 134A or whatever. The gauge showed it was at the very bottom of the blue range which is "Filled" so I shot in some more to get it to just under the top of the blue range. It feels much colder now but I'm seeing an intermittent problem where the compressor is not coming on when I think it should. In particular sometimes if I have the controls on MAX and the temp control lever on Cool the compressor is not on but then I can move the control to FRESH and the compressor kicks on and usually I can move the controls back to MAX and it stays on.
When the compressor is not on I can check that there is no power to the clutch and I can jump a power lead to the clutch and it comes on so somewhere prior to the clutch it's not getting power. Looking at the schematics I see 2 controls that look like they have to do with the clutch power. They are the AC Thermostat Switch and before that the AC Control Switch. I'm not sure where those are located or how to test them out. Are either of them vacuum controlled some way?
I'm also thinking about wiring up another power supply to the clutch. I was thinking of one of those little toggle switches with an LED light. Most have 3 poles. A negative, a positive in, and a positive out to whatever you are controlling. Would it hurt to wire one of those like that if the clutch is sometimes powered correctly and sometimes not? I wonder if the LED light will be on if the switch is OFF but the clutch has power to it from the normal source. I like the idea of an LED light showing me the compressor is on. Also this would provide the ability to have the compressor on when in defrost mode which I don't think it is designed to be.
I am neither a fast mechanic nor a slow mechanic. I am a half-fast mechanic.