I suggest you use the search function, this is a common problem and has been discussed a million times before. Because there is so much in the archives, I'll give just two quick suggestions. 1) Measure the air gap on the compressor clutch. Use standard feeler guages for this, such as are used for adjusting valves or setting the gap on spark plugs. The clutch gap should be 0.50m. If it's at or above 0.70mm you'll start seeing enough slip to trigger the protection circuit. 2) Clean any oil/grease etc off the compressor clutch surfaces. Use brake cleaner, simple green, whatever works for you. This can eliminate enough slip that the a/c works normally.

- JimY