1995 seville radio whine

hello22

My '95 Seville has developed an annoying whine in
the radio that goes up/down with the engine RPM.
It doesn't matter if it's AM/FM/CD/tape. It has
60,000 miles on it. Here are some observations I
made:

1. It only does it when the engine is warm.
2. The battery voltage is 14.1v cold engine.
3. The battery voltage randomly moves between
12.9-13.5v when the engine is warm.
4. Turning on the AC, seats, radio, head-lights
doesn't really affect the voltage
5. When the car is stopped at a light, it
typically reads a bit lower (closer to 12.9v)

I'm suspecting an alternator, rectifier, or
regulator. Maybe it's one unit in the alternator,
I really don't know! Any help would be
appreciated.

bobs5

Check battery voltage without engine running, typically should read 12-13 volts.

Now turn on headlights high beams and see if voltage drops, if the battery is going bad there should be a 2 volt decrease per bad cell.

If this is the original battery, it may be on its way out.

13.5 - 14 volts should be the correct voltage with the alternator working correctly.

I would suspect the battery in your case.

Good luck

hello22

I checked the battery voltage, and it was 12.0 on the nose! Turned on headlights (high beam), seats, and hit the brakes and it went down to 11.6v after about 10-20 seconds, then held steady.

The original battery blew up. It coroded the (+) teminal. I changed it, but jury-rigged it to. Could that be it? It's not the best connection.

I sometimes tend to suspect alternator prematurely. GM alternators don't last as long as they should.

bobs5

A good clean connection on the battery would be desirable.
Thats probably why you see a fluctuation on the battery voltage when the engine is running.
Otherwise, it seems you are on the right track to figure out this problem.

hello22

Changed the battery connection and it completely cleared the problem!