Whine Through Speakers With AC on

[PapaLazarou]

Hi,

Thanks for your time. I have just bought a 2020 Commodore LT stationwagon. When the AC is on and I have my iphone playing music (either through the USB cord or via bluetooth), I can hear a whine through the stereo that increases as the engine revs increase. It does not make this noise when the AC is off, or when I have just the radio on. It is the market stereo that came with the car. I have tried to search the forums but can not find anything related specifically to this. Any help would be appreciated!

 

[chrisp]

Hi,

Thanks for your time. I have just bought a 2020 Commodore LT stationwagon. When the AC is on and I have my iphone playing music (either through the USB cord or via bluetooth), I can hear a whine through the stereo that increases as the engine revs increase. It does not make this noise when the AC is off, or when I have just the radio on. It is the market stereo that came with the car. I have tried to search the forums but can not find anything related specifically to this. Any help would be appreciated!

Does it also whine with the headlights on?

Just as a guess, it sounds like an alternator issue. Perhaps it is producing excessive ripple under load (such as when the air conditioner is on). My guess is that it has a faulty diode in the alternator. As a starting point, check out the charging system (alternator, battery, connections , etc.) and work from there.

The other thing it might be is a faulty cooling fan or an air conditioner compressor clutch that is placing excessive load on the electrical system.

The headlight test should help isolate whether it’s a charging system problem or an air conditioner related problem.

 

[PapaLazarou]

Chrisp- thank you very much for your reply. I have not noticed if there is a change, so I will try the headlights on the way to work tomorrow and post back my findings. Thanks again!