Vehicle is a 1999 Chevy K1500 (4x4 half - ton) with a 4.3L engine.. Trunk has an aftermarket airhorn that is compressor operated.. The vehicle was running (at idle) when someone pulled on the horn to blast the airhorn.. As soon as the airhorn compressor came on the whole truck went dead.. Now it wont do anything.. No lights, horn, nothing.. Acts as thou a fuse has blown, or maybe fried a fuseable link.. Anyone have any ideas as to what to look for, where? Thanks, George