Radio Noise in Malibu

Fosgate87

Hello, when I use the A/C I get a high pitched noise in my Malibu on AM radio. I like to listen to talk radio on AM and this noise does not happen on FM. When I turn the A/C on full blast the high pitch noise gets higher and higher and then disappears but I don't want to blow the A/C so strong sometimes.

Also when charging my phone I get more noise interference to the point that I cannot hear the radio. When I unlock the doors I hear a static sound briefly as well. I went over a speed bump the other day and the noise disappeared temporarily. Weird. Any ideas what it could be? A mechanic and the dealership could not find a solution.

Thanks!