well my a/c system has been out for quite some time now and here are some things that i have noticed i hear rattling and hissing under the hood with it on and off, it blows hot air, and what seems to be rust<or similar to it> coming from the a/c compressor.
what should i do? right now i blame it on the previous owner who maybe retrofitted it improperly from R12 to R134A
thanks