RADIO INTERFERENCE WHILE MY GMC IS RUNNING
If you are talking about alternator whine, you either have a bad rectifier inside the alternator or the noise suppressor inside the radio has went bad. There are aftermarket suppressors out there, try someone like car toys, or Best Buy in the automotive section. If it is ignition noise then it is a good possibility that, A your plug wires are going bad, B faulty cap and rotor, C ignition coil bad ground.
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