All of the sudden everytime I turn my rear defrost on it makes the radio fuzzy. I have 2003 Crown Vic. I'm supposed to take it in for service but I'd like to have a clue before I get there. thanks.

 

I'm assuming you still have the factory radio?

My '99 Crown Vic does the same thing and soon I'll be converting it over with a nice sound system.

 

If your rear window is tinted and it has an antenna in the glass then its the tint causing the problem. Window tint has silver in it which is a conductor. You send 12 volts to the defog grid which causes the antenna to pick up the interference. If you have a seperate antenna you can just unplug the window antenna grid.