AKnott

I have a 2005 Mustang GT with about 91k miles and in the last month or so I have been getting this humming sound. It seems to get worse when I am both coasting and accelerating and also seems to pause for a second when the car shifts (it's an automatic). It's pretty sporadic. There's been times when I've been driving for 15 minutes and then it starts, starts right when I start the car, and I've gone a few days without hearing it at all. I don't know much about this sort of thing, but my dad said it could be the alternator dragging. I have already had the alternator replaced once a few years ago (not for this problem, it just died). Just curious if anyone has any ideas. I'm think of taking it to the dealer, but thought I'd ask here first. Thanks.

Glenn

so the humming sound is heard only while driving or can you hear it while in park also? Are you sure its not coming from the rear end?

AKnott

I hear it when it's in park also and I don't think it's coming from the rear end.

05PRMTX

Its not coming from the stereo is it?

KdF

First thing I would do is crawl under the tranny and see if the dust sheild is loose.

AKnott

I don't think it's coming from the stereo. I do have an aftermarket, Pioneer F700BT, that I've had for about 5 years now. I did notice today when I had to use my wipers that they move slow at first, like there's not a lot of power. After a few minutes they were fine, but each of the 3 times I first got in the car and used the wipers they were slow at first. And I will have to look at that, KdF.

Glenn

take the car to autozone and have them check the charging system

05PRMTX

Its fairly easy to rule out the stereo. Unplug it, run the car and if the noise goes away thats it.

Sounds like it could be somthing else though.Like Glenn said take it to autozone and get the charging system checked.

Glenn

they do it for free

AKnott

It's not the charging system. It's weird, though, I've gone almost a week in between hearing it so it's kind of hard to pinpoint it. It did it quite a bit today, though, and I tried to listen where it's coming from and it almost seems like it is coming from the stereo. What I don't understand, if it is the stereo, is why it seems to follow the transmission (get louder as I accelerate and coast and also pause when it shifts). I do know it is not coming from the rear end.

AKnott

You guys are good. My friend who installed the stereo said it probably is a ground issue somewhere. Thanks!

05PRMTX

Yep, Definately sounds like a grounding issue. Check and see how the stereo is grounded. If it goes straignt from the radio to the adapter harness thats probably why ur getting noise. Try grounding it to a solid peice of metal like the body frame or somthing like that behind the radio. Also, if you have rcas for amps and whatnot you might try grounding those as well. I had to do that to get rid of the noise in mine.