H3 Alternator whine

[derian06]

I have no speakers and no radio hooked up in my H3 at the moment yet I still have a alternator whine. The alternator has been replaced with a HO one. It goes up and down with the gas pedal/ engine rpm. I'm thinking it has something to do with onstar and the factory amp. Anyone know how to fix the issue, or does anyone know if taking out the factory amp/ onstar system will hurt anything? Thank you

 

[amrg]

I have no speakers and no radio hooked up in my H3 at the moment yet I still have a alternator whine. The alternator has been replaced with a HO one. It goes up and down with the gas pedal/ engine rpm. I'm thinking it has something to do with onstar and the factory amp. Anyone know how to fix the issue, or does anyone know if taking out the factory amp/ onstar system will hurt anything? Thank you

Did you check the grounding? I noticed that some HO alternators come with the Big 3 kits for wiring.
Which HO kit did you buy?

 

[derian06]

Did you check the grounding? I noticed that some HO alternators come with the Big 3 kits for wiring.
Which HO kit did you buy?

I have the big 3 done. And its a power bastards 250+ amp alt.

 

[JPaul]

Did you look at this from their FAQ?


"There is a noise coming from my alternator that sounds like a whine, whistle or squeal.
[SIZE=-1]Our high output alternators are equipped with an overdrive pulley. This pulley is designed to enhance low RPM charging for maximum output. The diameter of the overdrive pulley will be less than your factory pulley meaning sometimes, depending on the vehicle your factory belt may now be too long which could cause a noise. You’ll need to purchase the next shorter belt for your application, usually about 1" shorter compared your current belt if your current belt is too long. Your local parts store can easily supply you with the belt needed. Other areas of concern are the quality of belt used and the cleanliness of the belt and pulley system. Make sure each pulley on your vehicle is grease or oil free and use a quality belt like anGOODYEAR Gatorback™ Poly-V Serpentine belt or a GOODYEAR V-Belt™, depending on your application.
If the belt is the correct size and of good quality but the noise is persistent, check surrounding accessories like the idler pulley and automatic belt tensioner."[/SIZE]

 

[derian06]

I had the noise before the HO alt and after. I'll check the idler pulley and belt tensioner but I believe they are in good shape. I read that there was a problem with our specific on star models that causes alt whine. I'm going to go ahead and cut mine out and see if it gets rid of it as well.

 

[GreatDaneHummer]

Please keep updating derian06. I am interested in doing this same upgrade for all my lights and fridge running.

 

[derian06]

I disconnected the onstar fuse which is about 6" down from the positive battery terminal in the loom. Didn't have anything change. It's not a bad whine, but its there. Next i'm going to unplug the system from behind the radio and cut out the amp. If that fails I'll replace the tensioner/ idler pulley.

 

[chaos254]

I have the same issue with my stock alternator but haven't had time to look into it

 

[derian06]

Just finished re doing the Big 4 because the audio shop that did it for me did the big 3 and they did a bad job.
Alt neg to frame
Battery neg to frame
Battery neg to body
Battery pos to alt pos
I'm going to check tomorrow if the whine is still as loud.

 

[GreatDaneHummer]

Maybe try cleaning the engine bay out to eliminate outside variables?

 

[derian06]

Re grounded the radio

 

[JPaul]

Did that fix it?

Sent from my SM-N910T using Tapatalk

 

[Happy Hummer]

If this is the case, you can install an alternator noise filter on the power line between the battery and the alternator to minimize the problem. You can also install a noise filter on the receiver's power lead to cut down on signal pollution (American International's S15A (15-amp, 250-watt) or S25A (25-amp, 350-watt) filters, for example). Most often, however, backway noise comes from a loose or intermittent ground connection. (The preceding is not my work belongs to another)...lol.
Food for thought.

 

[derian06]

Did that fix it?

Sent from my SM-N910T using Tapatalk

nope

If this is the case, you can install an alternator noise filter on the power line between the battery and the alternator to minimize the problem. You can also install a noise filter on the receiver's power lead to cut down on signal pollution (American International's S15A (15-amp, 250-watt) or S25A (25-amp, 350-watt) filters, for example). Most often, however, backway noise comes from a loose or intermittent ground connection. (The preceding is not my work belongs to another)...lol.
Food for thought.

I wonder if the noise filter will blow since its an HO alt vs a stock one. I could try a noise filter on the power of the receiver.

 

[Reloader]

Is the whine comming from the sound system or from under the hood. I know you said speakers and radio are disconnected. If it's under the hood it should be mechanical such as bad idler or tensioner bearings . Or that new alt could be defective or NFG. A bad diode can sing like a banshee too which would indicate a bad alternator too. If that fancy alt has an overdrive pulley and the belt tension can't be maintained the belt could be squealing but that would be very obvious and power steering would suffer also.
just cause something is new or rebuilt doesn't mean it's always good or remanned . A reman job can just be a DuPont overhaul.

 

[derian06]

So I just checked everything out It turns out I still have some tweeters in the pillars. So I turned the volume on the radio all the way up and revved the engine and got no alternator whine. Re grounding everything must have fixed it!

 

[Happy Hummer]

Cool. Thanks for follow up. Still quiet?

 

[Happy Hummer]

Must say that rig of yours is really turing out nicely... wow!
Pics pls.