Could a failing Alt. cause Alt. Whine?

[av8ter 10+ year member]

I am getting excessive alternator noise in my friends blazer. We have ruled out the RCAs, headunit ground/wiring, headunit, amp ground, and we have tried grounding the rcas.

Nothing has prevented except for me running a set of rcas from my headunit in my car over into his amp installed in his car. We both have alpine radios so we have swapped each others and the problem still occurs in his car.

His alternator is the last thing I can think of.

Can anyone back this theory up or guide me in the correct direction?

Kevin

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[tydie_05]

do you have the RCA's ran next to the power wire? sometimes that is a cause of the alt. noise. try running the RCA's on the opposite side of the car as the Power wire

 

[av8ter 10+ year member]

Not even close. The closest they come is when they attache at the opposite sides of the amp.

 

[gnatnoop 10+ year member]

are you hearing the alternator thru the stereo or is the alt just making noise (whining)

 

[michaellane 5,000+ posts]

i got it also. *****. i cant figure out what the problem is...and my rca's are ran on the oppisitre side of the car as the power wire

 

[av8ter 10+ year member]

Engine noise is coming through the system(amped mids/highs and subs). Only happens when car is on.

Most mind boggling test I have done is contolling his system with the headunit in my car, both cars running, and rcas running from my teg to his blazer. Zero problems when this is going on. It is just his car's electrical system clashing with whatever Headunit it is connected to.

The only thing I can think of is just the alt.'s regulator is shot or something introducing excessive ac voltage into the car's circuitry.

Any thoughts?

Kevin

 

[gnatnoop 10+ year member]

Engine noise is coming through the system(amped mids/highs and subs). Only happens when car is on.
Most mind boggling test I have done is contolling his system with the headunit in my car, both cars running, and rcas running from my teg to his blazer. Zero problems when this is going on. It is just his car's electrical system clashing with whatever Headunit it is connected to.

The only thing I can think of is just the alt.'s regulator is shot or something introducing excessive ac voltage into the car's circuitry.

Any thoughts?

Kevin

well if you have tried everything you can think of in his car, checking all grounds, running good rcas away from power wires, changing headunit etc.... the problem is most likely in the engine compartment, there are a couple things you should take a look at first, such as the alt. there is also something else in the engine compartment called a noise suppressor (this may be a shot in the dark).. its main function (i believe) is to keep engine noise out of the stereo.. i had this disconnected in my truck and it made a difference.. what year blazer is it, i will try to find a schematic for it real quick to show u what im talking about

 

[av8ter 10+ year member]

It is a 1994 s10 blazer "tahoe" edition.

Thanks dude.

Kevin

 

[Adnan 10+ year member]

check the battery terminal wires and grounds...could be be caused by corrosion

 

[av8ter 10+ year member]

Will check them tomorrow when he is over at my house and I am going to go ahead and do the battery to chassis ground in 1/0.

Kevin

 

[stocker08 10+ year member]

Engine noise is coming through the system(amped mids/highs and subs). Only happens when car is on.
Most mind boggling test I have done is contolling his system with the headunit in my car, both cars running, and rcas running from my teg to his blazer. Zero problems when this is going on. It is just his car's electrical system clashing with whatever Headunit it is connected to.

The only thing I can think of is just the alt.'s regulator is shot or something introducing excessive ac voltage into the car's circuitry.

Any thoughts?

Kevin

For reals? //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[av8ter 10+ year member]

Yeah stupid statement on my part haha.......

 

[stocker08 10+ year member]

Its all good. I got this problem too. Kind of ***** but isn't a killer.

 

[av8ter 10+ year member]

Nah, dude, i am pretty sure this is why his Pioneer 6100ub and Powerbass 3000d straight up died.

This problem is killing his wallet haha.

 

[av8ter 10+ year member]

bump, da bump da bumb........

 

[PaulD 10+ year member]

try putting an ipod or whatever straight into the amp RCA inputs.

 

[av8ter 10+ year member]

Tried that and it is completely fine without and alt noise.......

Kevin

 

[smoka 10+ year member]

I know you said you checked the grounds, but you might want to double check it with this test.

RCA's provide a ground link between the deck and the amp. If there is any current running through that link then you get noise in the signal.

Here is a test you can try to check your grounds. Do this with the radio on and the whine present.

Get a 20ft small wire. Attach/clamp one end to your neg batt terminal. Attach the other end to the neg voltmeter lead. Set your meter on DC volts. With the red lead, check for any voltages at your amp ground points, you may also want to try your deck ground point.

You should see something very close to 0v. But if you see anything strange, even a couple of mV. That could mean a voltage potential exists. Sometimes an amp takes care of that potential by grounding through the rca's.

Did you ground the rca's at the deck? If the excess current is coming from the amps, then the signal is already damaged by the time the rca's ground out at the deck. You might even want to try grounding them in the back also.

Hope this helps.