Is my alternator going out?

[df2x4]

The whining through the stereo speakers can be noise from failed diode(s) in the alternator, but can also be a poor ground in the stereo wiring - especially if it's got an aftermarket unit, depending on how it's wired in, and whether or not there's aftermarket amplifiers in the mix.

Richard

One of my dad's earlier 400s did this straight from the factory when it was new. Very slight alternator whine through the stereo when it was powered on. Seemed to be most noticeable when playing a cassette IIRC. He had it fixed under warranty but unfortunately I don't remember what the cause was... I'd bet on a ground issue though.

 

[slow_c1500]

You said “new sounds”.

Is anything else “new”, such as a recent change, ANY change, made to the vehicle… electrical OR mechanical?

Re: Alternator noise in the radio, this can be caused by a “poor or improper ground upon installation” of a new unit OR a “good ground gone bad” on an existing unit.

In the latter case, it’s possibly due to a failed or failing OE ground strap, but could be elsewhere.

It has an aftermarket radio but that has been installed for about 2 years. I’ve changed the fuel pump, and I switched the taillights, third brake light, and turn signals back to oem halogen from LED. Not sure if any of these could possibly be related.