Alternator whine from the OGM-1?

[jhale2004]

I pulled the radio out again and tried to move wires around hoping to help it out and still nothing. I did unplug the radio and with it unplugged the whine is almost gone comepletely but plug it up and you hear the whine again. I dont understand it. It isnt a whine played through the speakers cause the speaker harness can be unplugged and you still hear it. About tired of messing with it so I guess I will have to learn to live with it but damn it drives me nuts. So does my seat creaking when my weight shifts. Maybe I am just too picky. Haha.

[jhale2004]

I wonder if there could be somethin going on internally with the radio causing this whine?

[dyakovly]

I used to have whine on Factory navigation unit and I did try all mods to kill it, no luck at all. So, got ogm1 and I'm still have whine ( Maybe Walt will crime on this problem with solution?

[iceman1998]

I've often wondered if the sound is coming thought the Onstar mic/ speaker in the roof

[wottenad]

What you guys are hearing is indeed alternator whine, but the cause and solution(s) are not nearly cut and dried.

 

Remember that the alternator generates an AC signal that is converted to DC and passed to the vehicle's electrical system and battery. Engine noise is nothing more than some AC signal generated by alternator not being effectively filtered, and this can be due to dozens of factors, including bad diodes in the alternator, a weak battery, poor signal wires, signal wires being run too close to power wires, etc.

 

GM has a very well-known issue with noise in the factory systems of some, if not all of their vehicles (Google it). Factor in that only a very small percentage of people can hear this noise, and it doesn't rise to the level that GM is taking it seriously, so they've not done a redesign of the amp or signal paths. Now add in an aftermarket head unit (any head unit - it's not specific to Advent), and you have the chance that even a small increase in noise caused by the deck brings it to the level that more people can hear it, and now it becomes a bigger problem. I don't think this is 100% the fault of the car or the deck you install in it. It's a combination of factors that have to be worked through to be able to tell what the causes and solutions are.

 

Most of the time, engine noise can be eliminated very easily by making CERTAIN that all the components in the system share the same ground. This means that a wire is connected to each component and is physically connected to the same piece of metal. To make a long story short, you have to insure they all "see" the same ground to make sure that any AC noise generated by the alternator has an easy (and the same) path to ground from any component in the system.

 

When we're working with factory systems, the ability to troubleshoot noise is SEVERELY limited because we don't have any easy way of getting into the signal path to insert filters or of filtering the power supply lead for the amp, or running separate grounds for all the components. The head unit plugs in and the amp plugs in. There's not much we can do to get in the middle, and it is very difficult to do in a GM truck or SUV with Bose because you have to shred the console to get to the amp, then you have to take out the deck, and last but not least, you have to insure the antenna is grounded in the same spot. So, the most effective way (though not the only way) of dealing with the problem is also the hardest thing to do!

 

You could convert the RCA outputs of the OGM1 to plug into the factory radio harness so you'd be able to insert filters inline, but this is a huge step that may or may not have any impact on the problem. You could re-run power to the factory amp. You could relocate the factory amp so that it's not physically mounted to metal. You could eliminate shielding on the antenna (but you'd cause WAY more problems with engine noise on the radio...) You could filter the power lead to the deck. You could replace the battery. You could test or replace the alternator.

 

In other words, noise issues can be so convoluted to deal with that you really have to be methodical, patient and VERY observant to effectively deal with them. I don't want to brag too much, but I've always been the "noise guy" in every shop I worked in, and the issue in Bose-equipped GM vehicles is a tough one to get a good plan of attack for, because almost all of the methods to test the theories involve replacing factory components, which is next to impossible to do, but is really the ONLY way we can determine what the fix may ultimately be.

 

Wish I had some better news, but I think that maybe the best bet here would be to "crowd-source" the fix, by taking everyone's experience and try to add some logic to it to see if there's a likely candidate for a solution for the majority of the people that have the problem.

 

BTW: if you're over a guy over 40, you're probably wondering what all the fuss is about - it's highly unlikely that you can hear any engine noise in your system without putting your ear on a speaker grille - I know I can't...

[jhale2004]

Even with the whine I wouldnt take anything for my Advent unit! I hope we figure it out one day but I will learn to live with it for now. Thank you Walt for your top notch service!

[Doug_Scott]

If the whine is new, look hard at any changes that have been made recently. As for common grounds for all components, you can snake a wire around from component to component (just like house wiring does with the ground wire in the boxes). All you are doing is making the potential difference the same for all devices. I noticed that my stock radio that came out of my truck has a plastic chassis. That sort of thing will make it hard to get a common ground.

[wottenad]

If the whine is new, look hard at any changes that have been made recently. As for common grounds for all components, you can snake a wire around from component to component (just like house wiring does with the ground wire in the boxes). All you are doing is making the potential difference the same for all devices. I noticed that my stock radio that came out of my truck has a plastic chassis. That sort of thing will make it hard to get a common ground.

 

 

Yeah, but if you look closely, the plastic housing has a metal mesh embedded in it for noise reduction...

[aesalazar]

Glad I am not the only one who notices the wine. It has always been there but chalked it up to my amp or something associated with it.

 

Only notice it with the volume down and not moving...

 

Ernie

[tanked_darren]

HELP. My sirius dock I have in my truck makes a slightly louder alternator whine now that I have ogm1. It only happens with the engine running and changes with RPM.

 

The facts:

Sirius starmate 5

Aux cable connection (high quality cable)

12v power piggy backed off a cig lighters wires behind the dash

Whine is only with engine running NOT with key on engine off

 

I really like Sirius and want to fix this!

[tanked_darren]

HELP. My sirius dock I have in my truck makes a slightly louder alternator whine now that I have ogm1. It only happens with the engine running and changes with RPM.

 

The facts:

Sirius starmate 5

Aux cable connection (high quality cable)

12v power piggy backed off a cig lighters wires behind the dash

Whine is only with engine running NOT with key on engine off

 

I really like Sirius and want to fix this!

Screw it I'm going with the fm transmitter

 

Sent from my Nokia 5190 using Tapatalk 2

[wottenad]

HELP. My sirius dock I have in my truck makes a slightly louder alternator whine now that I have ogm1. It only happens with the engine running and changes with RPM.

 

The facts:

Sirius starmate 5

Aux cable connection (high quality cable)

12v power piggy backed off a cig lighters wires behind the dash

Whine is only with engine running NOT with key on engine off

 

I really like Sirius and want to fix this!

 

 

I noticed in your earlier post you said the battery was completely dead - is it possible you have a very weak battery? Alternator whine is mainly a result of a weak battery, since the battery is BY FAR the biggest alternator noise filter in the truck.

 

Do this test if you can: see if you can talk a buddy into swapping the battery from his new truck into yours. When you get the new battery in, start the truck and turn on the headlights on high beam. This makes the alternator work as hard as it can, throwing out the most noise. If your old battery was the culprit, you'll hear less noise through the system with the new battery. If you hear less noise, replace your battery with a new one.

 

If it stays the same, the next step is to try filters, but it gets MUCH tougher to eliminate if you have to go that route.