Audio Systems: 1998 ford f150 radio, radio antenna, non polarized capacitor

Question
hi thanks for taking my question.when i have my radio on am,then put my foot on the brake i get static.take my foot off and it goes away butttt!!!this will not happem on fm .i unpluged the brake switch from the peddle and the static was gone .but i have no brake lights(thats no good ).so i replaced the switch and the static is still there, unplug it and it goes away .whats a man to do thanks.

Answer
You have a classic example of a switch introducing noise. When horn buttons would cause it, it was referred to as "horn hash". The easy solution is to add a non-polarized capacitor across the brake switch leads. Should fix it right up. The more difficult solution is to replace the radio antenna from fender to radio (all), and figure out why the fender is not grounding as well as when new. My guess? Rust.