Tony Brookbanks

Hi, I recently had my factory stereo upgraded to a pioneer unit. It works fine during the day but when I turn the headlights on I get a loud buzzing sound from both rear tweeters it is too loud to just ignore. This is where it gets strange... If I turn the headlights on during the day (either on auto or fully on) the same noise does not happen. The buzzing will only happen at night (darkness) so im thinking when the headlights are "on" during the day they are not at full power so do not interfere with the audio system/speakers. Can anyone confirm this is the case and if so where the light sensor is located as I need to be able to take the car back to the car audio place (during business/daylight hours) and show them the problem. If I can cover the sensor and trick it into thinking its dark would be a huge help in replicating the fault and getting it fixed. Vehicle is a 2007 a4 2L turbo B7.

-Thanks

Manjo62

Who did the aftermarket install? What is the make of the aftermarket radio? I did this on my 09 on my own and I do not have issues, if you are able to remove the radio then you can check few things. Here is link that explains all the connections in detail. I did not use Enfig but bought my kit and harness from Spiral Audio for 50% cost of Enfig and it is exactly the same.