hey i have a 2000 chevrolet s-10 4cylinder. i have a high pitch alternator whine through the speakers and idle and when i the rpm goes up the whine gets louder. the dash lights and the radio lights flicker at idle and get better once i give it gas but still flicker alittle. i have a new battery and have replace alternator with a factory replacement. the whine noise is still there with the flicking lights.

so then i wired in the battery feed wire to the radio a 20 amp noise filter. this has stopped the whine noise through the speakers but i still have the flicking lights on the dash and the radio. can any one help me?
thanks

Check that you still have your dash & radio ground's. There are 3 ground's for the dash.Left, Center, Right.