1977 L48, factory air. Guys, I need your help. I have installed a new compressor, accumulator, etc, and recharged the system. It blows nice, cold air, but I have run into a snag. The compressor will not cycle, and it runs constantly, causes the line to freeze. I don't know if bubba worked on it before I bought it, but here's how it's set up. It has a thermostat cut off switch mounted next to the accumulator, with two wires coming off of it, but I just discovered they are not attached to anything. The thermostat sensor is attached to the a/c line. I'm assuming when it reaches a certain temp, it opens and closes the switch to shut off the compressor, but as I said, the two wires are not tied into the compressor. The system also has the low pressure shut off switch that screws into the a/c line along the passenger firewall. Two wires come off of this switch. One goes to the compressor, and the other goes into the wiring harness. I can manually shut off the a/c for 5 seconds and the ice on the line thaws out, so I'm convinced this system should be cylcling on and off. What I need to know is how do the two wires from the thermostat tie into the compressor or the cut off switch. It's a green wire and a light blue wire coming off the thermostat switch, located next to the accumulator. Where do they go?? If anyone has a '77 with this setup, could you look under the hood and let me know, take a picture, or direct me to a wiring diagram. I'm so close to having this thing work right, it's driving me nuts.
Thanks,
Kenny

 

P.S. The thermostat cut off switch and the low pressure cutoff switch are also brand new.

 

There are a number of switches that can be used to make up a system.
From your description yours seems to have what I call a freeze switch. Hook it up in series with the other.

Slightly more modern systems have a high/low pressure cutoff switch and also a low pressure cycling switch mounted on the accumulator.

If both the switches you have are 2 wire then just wire them in series and it should work.

 

If the pressure switch works all you have to do it put it in series with the compressor clutch. I don't have the drawings, but if you pm papawana he will send you what you need

 

Here's offer from papawana;


http://forums.corvetteforum.com/c3-g...or-anyone.html

 

tttt

 

http://img39431.pictiger.com/images/17922216/

here's the haynes diagram.