My A/C compressor will not disengage. I have to pull the relay from under the hood to shut it down or else it runs my battery down. When I do attempt to use it, it freezes over after about 1 hour of use and then it stops blowing air through the resistors (vents) on the dash. This is on my 2001 Chevy Silverado that has a 4.8L under the hood. I had the A/C compressor replaces last summer and it worked great, but not working so well this summer. When I replace the relay, it blows cold air and it will freeze you out till it freezes up. Seems like nothing on the dash (the controls) have any affect on the operation of the unit. Any help on this would be greatly appreciated.