Hello everyone. I'm new to the site and hoping for some good info. I just bought a 2005 TL all stock. When the engine is off the sound system is fine but when i turn the engine on a buzz comes through the speakers. When I rev the engine or turn the A/C on high the frequency of the buzz follows through the speakers. When I turn the engine off everything turns off at first but then speakers come back on and the buzz slowly goes away. Is there an ignition audio filter in the car dash, Maybe alternator going bad? I think the amp and grounding are fine because it only occurs when the engine is on. TY

 

Check the easy stuff first; check the spark plugs to see if they match the factory recommended plugs. If they're not the correct plugs, I suggest you change them to see if the buzz goes away.

 

Do a Google search for Active Noise Cancellation.

 

The mic doesn't seem to work. I entered into mic diag but the meter doesn't move Thank you

 

Battery terminals are tight and clean. All the molex wires near the amp are secure. it is all stock still