auto67

Yeah mine just started doing that also. I thought it was coming from the speakers also till this morning I started it up to warm up and when I came out of the house I heard it whining from my house. Seems to do it mostly around 1800 rpm for me. Im sure its the alternator.

WIF-150

It never does it at startup or when in neutral if I give it gas. Just when driving between 1500 -1900 rpms. I think it is the alternators

WIF-150

Will a bench test tell if the alternator is bad? I have no dim lights, no slow starts, battery is good. Just the damn whine.

MNgopher

No, a bench test will not find this issue. More than likely it is the alternator though. Replacing mine got rid of that sound when it is cold. The flip side is if you can stand the noise, it doesn't seem to affect the life of the alternator. My work vehicle is still making that noise 10 years in...

HuntO

Mine is having the EXACT same issue! Started last week, and its driving me insane. Truck runs perfectly fine, it just sounds like a power surge coming through the speakers from 1500-2000rpm, mainly around 1800rpm. Did you try replacing the alternator by chance? Or did you find a cure?

Thanks!

WIF-150

Well good to know its the alternator, at least thats the way it seems. I was under it for a hour yesterday checking every wire and connection I could. Hunt-o I havent changed it out. Not sure if I will if I can stand it for the winter and it goes away when it warms up I'll change it then. But if I can't take it I might do it this winter. Looks like a pain, every other alternator Ive ever done was super simple, didn't have to really take anything apart to get at it.

ajack

Same thing has happened to my truck for the past couple winters. Never seemed to effect anything. I have a friend at work who had an aftermarket radio in his car that did the same thing. Ended up being some kind of ground issue. Mine isn't too annoying and usually goes away after the truck warms up all the way so I'm not too worried about it.

WIF-150

I hope its not a ground or wire rubbing. Would be a pain to try and figure out, nothing on this truck is easy to get at