Alternator whine (?) coming from speakers when AC is on

[LettiM3]

I have a '24 Ranger Raptor and since day 1 of ownership I have had what I believe to be alternator whine coming from the speakers when the AC or climate control is running. When I hit the power on to the climate control, the noise starts through the speakers and is RPM dependent. The whine comes through whether the stereo is turned on or off. When I turn the climate control off the noise immediately stops. The vehicle is stock without any stereo or electrical modification. I will be taking the car in for service and will mention this to the deraler, but wanted to run the issue by the community here to see if this has been discussed and / or addressed with a potential fix. Has anyone experienced this?

**I have seen a few other threads mention this but no definitive resolution.**

Sponsored

 

[unixadm]

It's probably the noisy AC compressor and not related to the charging system. Have everything on like normal and replicate the sound. Then hit the AC button and see if the noise stops. If it does, it's the compressor. There doesn't sound to be a fix if that is the case.

 

[josephp732]

What you described, alternator whine, characterized by a high-pitched noise that varies with engine RPM, typically occurs when the alternator's electromagnetic interference affects the audio components. Do you hear the wine in all the speakers or just the dash speakers?

Usually there are two possible issues:

1) Grounding Points: Poor grounding can allow electrical interference from the alternator to leak into the system.

2) Faulty Alternator: A malfunctioning alternator may produce excessive electrical noise.

The dealer should check the alternator - easy to do. "I think" the issue is probably a poor ground.

I would ask the dealer to check all the factory ground points. On my 2025 Ranger Lariat, I found 1 engine grounding point that was not attached and 1 grounding point that was attached to a painted part of the frame.

If you hear it in all the speakers (the truck has two amps), then I think it's what I noted above. If you only hear it in the dash speakers, that's the amp that in the head unit, if you only hear it in the doors and rear speakers, that the rear amp. In either case those would lead me to believe there is a local grounding issue with either the head unit or the rear amp.

 

[andymacks]

Fixed. See other threads or my posts for details.

Sponsored