I put an LT engine in my 63 Pontiac and as the original car did not have a/c I built a unit out of junk parts and adapted all the factory parts off of the donor truck. Compressor, condensor, evaporator and hoses. Logic was if the unit worked good in the truck it should work good in the car. It is a variable compressor which I know nothing about but was advised to just power up the adjustable vanes with the clutch circuit and it should work. Apparently it was originally controlled with the ECM but it now has a modified ECM and wiring.
The system was working fine until sunday when it started blowing hot air. Today I put the gauge on it and the clutch was on and off rapidly at idle and the low pressure gauge was at about 10 pounds. I tried putting some refrigerant into it and as soon as I added a small amount the compressor started locking up and slipping the belt, sounded like I had run over a cat!
With a minimal amount of refrigerant in it what would cause the compressor to lock up? Should I just replace the compressor and see what happens? I got out of auto repair in the late 70's and have not kept up.
Thanks for any knowlegable advice
Dwight