2006 Chevrolet Impala • 122,500 miles

I have 2006 chevy Impala, In the fall I had error code on the screen that said, Engine overheating A/C shut off. This code only came up once and I thought it was because my coolant was low. Refilled Coolant everything was fine, Now my AC is not working, I just had freon put in because I thought I was out, Now it keeps blowing the 10 amp fuse. Any ideas what is going on? Chevy said they would have to do a diagnostic $ 90.00 and if it's AC compressor wit labor is $ 890.00 and I just don't have it. A few months ago the throttle body went bad and they did a diagnostic then wouldn't the code come up? Can you give me any tips how to Diagnois the problem myself?
April 17, 2012.

Remove the A/C belt and turn on ignition and A/C check to see if the clutch is engaging, and with the A/c off ensure that the clutch is released start here.

Apr 17, 2012.
Can you explain better? (And with the A/c off ensure that the clutch is released start here) Are you telling me to unhook the belt and see if the clutch engages wit the ac on and engages wit ac off? And if does engage what could be causing the fuse to blow? And if doesn't engage I take it that means it needs a new clutch?

Apr 17, 2012.
What is the marked for?

May 2, 2012.