I was driving into town yesterday and had my A/C on. I was driving by a car wreck and shut my radio and A/C off. After I shut the A/C off I heard a sort of rattle by my speaker in the door. At first I thought it was my speaker but I turned the radio off. Could it be a fan bearing or ? The rattle goes on for probably 8-10 seconds after the fan is turned off. The fan still blows the same as it used too. I also have another question about the radio. I got a radio at the Junkyard and put it in my car, of course it was in safe mode and I couldn't find the radio code in that car. I also got the instrument cluster from that car to use for parts. I plugged the speedometer into my car and tested it. It wouldn't light up and the gauges didn't work. So I put my original cluster in and tried to turn on the radio again and it worked! It wasn't in safe mode anymore. Does the instrument cluster unlock the radio? Thanks for any response!