Thermal Limiter Circuit ??? Anyone??

I am trying to find a circuit diagram so that I can understand what I believe is the "thermal limiter" circuit coming off of the back of my A/C compressor on the '72. This is a single wire going to one of three ports on a "thermal limiter", which I think is like a fuse?
Can anyone out there explain how this circuit works?!?!
Also -- does anyone know where I can get the correct thermal limiter replacements?

Thanks!
Bill
72Warbonnet

i will email you a wiring diagram. Anyone else that would like a copy email me at gmackner@yahoo.com as far as the thermal limiter replacement i would think you can get them at through any corvette catalog and at most auto part stores. They are pretty common to all GM cars. i have an old one from years ago made by Victor Automotive, Des Plaines,IL (part #V-909) it says it is a replacement for GM part # 6556440