Hey guys, on my '90 1500, with the engine running, when I turn on the stock radio, there is a kind of "frequency pitch sound" that eminates from the speakers, and the pitch changes when the engine RPMs change.

I was told that there is supposed to be some kind of "capacitor" kit that you hook up to the alternator which is supposed to suppress that sound from the radio.

Have any of ya'll had this type of problem?
Let me know. Is there such a kit that can be purchased at the auto zone / pep boys, etc. that will fix the sound problem?

Thanks.

'90 1500 ext cab SWB 5.7L auto tranny. Daily Driver
'03 1500 std cab SWB 4.3L auto tranny.

Check your radio ground, make sure it's good and solid.

Also make sure your battery is grounded really good to the frame, ditto for the alternator.

Just checking and making good ground on all 3 of those points (radio/alt/batt) will help engine whine a lot.

Also a bad battery (one that's not in top form) can also add to engine whine.

You can also get a ground loop isolator, they're supposed to help. I've usually fixed my problem with engine whine by just making my grounds really good and solid.

You hav'nt replaced the plug wires lately? Some spare plug wires will cause it.

Alternator noise, caused by a diode that may be going bad or a bad ground.