last winter, i decided to replace my factory radio with one of those fancy sony cd/ mp3 players. installation was awful. ive installed some stereos before in a number of different trucks, but the lc is a real pain for a stereo switchout. everything seemed to go well. however, as i was riding around enjoying my new tunes, i realized that there was a noise now coming from the heater. it sounds like something is stuck in the fan. it still blows hot , but it is now noisy whereas before it was quiet. well, now that summertime is here, my ac unit only blows hot air. has anyone had similar problems after a cd player install? my friend is a really good mechanic, and he tested freon compression and said it is good. he also looked up the ac wiring diagrams and traced all wires to the blower and fuses with a wire tester, and all was good. i also took apart the dash again, and everything "looks" good. has anyone ever had to replace the ac/heater control in the dashboard? any info would be appreciated.