After about 30-45 minutes, the A/C freezes up and the fan slows down. Upon checking, I've found that the compressor never stops running. I've been just turning it on and off at the dash switch every 10-15 minutes. I've checked and cleaned the aspirator above the mirrow, it runs OK. Any help/suggestions please. I really would not want the dealer to get hold of this and wind up with all new parts til he hits the real problem.

Ron