help with an alternator whine problem

[matthewo 10+ year member]

well i have had multiple different amps in this car. and 2 source units including the stock one. everyone who owns this car has the dreaded alternator whine. the alternator actually makes a whining noise sometimes when the car starts that sounds like a supercharger(very noisey alternator).

right now i have the headunits power and ground connections run directly to the trunk and connected to the battery(fuse) the audison bitone processor is tapped in and fused off the same deck power wire. this was the cleanest way i could wire it, but i still have a bit of alternator whine. without running the power and ground of the deck to the trunk the whine is even worse.

the system is perfectly clean, NO whine when i used the decks digital coax output directly into my bitone processor digitally. so this tells me the problem is before the processor, and has nothing to do with after the processor.

i have a stinger ground loop isolator hooked up to the rcas input of the processor right now. it has 2 wires that come off the ground loop isolator. i think they are the sheilds of each rca cable??? when i tie them together the alternator whine almost goes away, when they are apart its pretty much the same and not even worth using the ground loop isolator.

could the problem be that the rca sheilds just need to be tied together and not even use a ground loop isolator?

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[SmartAsss 10+ year member]

the system is perfectly clean, NO whine when i used the decks digital coax output directly into my bitone processor digitally.

Quick question, why would you not take advantage of the digital output since you have that luxury? Also why do you have the wires running directly to the battery? that can give you two different ground resistances if your headunits metal chassis is grounded also.

The ground loop isolator wires are most likely meant to be grounded. but I would remove it while trying to isolate the problem.

 

[matthewo 10+ year member]

I do use the digital out a lot of the time. But it doesn't work with fm, sd, or USB input. I like to use the USB with my external hdd and wav audio.

I think the decks chassie isn't grounded.

 

[SmartAsss 10+ year member]

Have you tested the headunit on the factory's power connections yet? might want to try that first. Im not positive but i think i've heard reports that the bit-one has a little bit of a high noise floor. Are you hearing the noise at lower volume or at higher volume? ground loop isolators are sort of gimmicky and don't really address the real problem.

 

[PTG]

Alternator whine, and some other types of noise, can, and often do, require some tedious and step by step troubleshooting. Without physically examining your setup, I will try to give you some basic things to check. First, keep in mind that the metal chassis of the car is one big ground. If done properly, there is no need to run grounding wires all over the place. Check your ground connections making sure any and all grounds, have good connection to the chassis. Scrape away any paint and primer, use a bolt, star washer, and nut when at all possible. Make sure your source cables (RCA) are run away from your power connections. If they must come close at some point, make sure they just intersect and then head away from each other again. (In other words, not parallel to each other). Get rid of the ground loop isolator. In most cases those things create more problems than they solve. After these few things, if you still have whine, get back to us. One thing also kind of stands out, you mention that the alternator makes a noise like a supercharger. I'm no expert in that field, but that's certainly not normal. An alternator that has bad brushes, etc. can amplify some of the issues you are trying to get rid of. You may consider taking it to a service center and have it tested. Best of luck.

 

[matthewo 10+ year member]

Yeah, for this car it's normal. On the "g8board"(car forum). It's very common for people to have alt. Whine even using factory deck. I have herd in some cases even totally factory auto system has some whine. I removed the gli and upgrade my engine to chassie ground with a 2/0 cable and running from the back of the alt to a unused bolt hole on a solid part of the chassie. I think it helped a bit, let me remove the gli and keep the alt whine still very modest, but still there. The chassie to battery ground already was upgraded. I'm going to run new RCA cables Monday using rg59 or rg6 cable. Basically a coax cable with RCA ends. The same type of cable I'm using for my digi connection that has no whine. I figure the digi connection has no whine cause it's digital but I'm only using a lower model stinger twisted pair RCA ATM.

The bitone has a pretty low noise floor from my experiance. I went from a rf 350.2 to it 2 years ago and never lookedback. The rf was full of whine, and the air hiss sound when nothing playing

 

[matthewo 10+ year member]

Even as it stands now the whine isn't too bad. At least now i don't have to use the gli and that makes me happy. Even If I just get a tinny improvement from new rcas I will be happy. I'm going to run them up over following the roof line away from all other car wiring. While I'm back there I will play with the decks ground and power.