AC Pressure Jumps to High
 

I have a 2000 Chrysler, 300M. The other day my AC Compressor locked up on me and was barely turning, trying to burn up my belt. I bought a Compressor form local Salvage yard. I start to fill with cans till my pressure is good. Now, when I put in one can, the lines gets to a low normal running pressure,,,,and then a small squirt of the next can the pressure will automatically jump up in the red zone like somethings going to burst and the pulley starts to freeze up because too much pressure for the compressor.
I then installed a new Expansion Valve and new Dryer (incase of blockage). Also before that I tried to rinse/and blow out all the lines. The big thing I notice is as I fill the unit,,,the clutch kicks in only once and NEVER cuts off. Unlike Im accustomed to as when you build up pressure in the lines the Clutch kicks on and off. More frequent at first and as pressure builds it slowly stays on more then off. High pressure Switch????? If so,,,Where the heck is it?
Thanks for any help,
From Tom

I take it u have never put freon in a system b4 have u?

Simple rule of pressures U can not over come one pressure unless the other is higher.

So if U have 40 psi in the system the can has to have more psi inorder to shoot the freon into the ac system or using the compressor to make a low pressure and allow the can to be sucked into the system put 2 cans in and call it a day dont look at the pressure until the second can is all the way in U should need about 24oz or 2 lbs.

This would have been about the hundredth time during my years, thinking I could add a couple cans and keep cool. I understand the logics, BUT,This IS the first time I ran across this problem. My point is that I get so much head pressure (even on a small amount), like 1 1/2 cans, that my compressor cant spin anymore and the CLUTCH REFUSES TO DISENGAGE at any time. And rule out the Expansion Valve, its been changed.