Hey guys,

I've done some searches and have read plenty of threads on here about this all-too-common problem. I know that everybody is getting sick of reading about alternator whine, but the question I have is more specific than most.

I read once on here that alternator whine can be caused not only by a bad HU ground, but also by a bad connection to the batt. When I hooked up my HU, I did not ground it in the best of locations. I recently changed the grounding location, and the whine has not gotten better. It's grounded to a bare-metal support piece behind the dash, so I know the ground is fine now.

For the positive wire, I used the one coming out of the harness adapter. In other words, I DID NOT run a dedicated wire right to the battery for my HU. I'd read once on here that this could cause alternator whine in the system. I know for a fact that when I go back to the amps and disconnect the RCAs from the inputs, and stick my iRiver directly into the input, the whine goes away. So I know it's definitely coming from the HU. Both the HU and the amp grounds have been changed and are definitely good. (both are bare metal, etc.)

So is it really possible that my whine is being caused by the lack of a positive wire right to the battery? I know the stock HU must've used less power than this one, but considering I have the internal HU amp shut off, is this really the case?

If this isn't the problem, than the only thing left to do is screw with the actual battery-chasis connections, I guess. And I really don't want to deal with that.

Thanks for the help.
-Brian

 

If you unplug the RCA's and the whine goes away, maybe its your RCA's?

 

Well, they were the cheapest ones Best Buy sold. But I don't have them anywhere near the power stuff, except for in the trunk where they cross at a 90 degree angle. Could this really be the problem?

 

pretty sure Ive seen don say it a few times, that whole RCAs around power wire is jsut a myth....but im in the same boat as you are.... HU grounded good, even changed still whine...changed my amps ground point, still there.....so i say screw it and just turn it up more the music will drown it out......... allthough i have not messed with the battery terminals or anything like that at all... ill be followin this thread close also, its a pita when sometimes blastin just isnt called for....

 

Yeah, I don't like the idea of having to blast the music just to get rid of the whine. It bothers me most when I have the thing paused or turned down b/c I'm talking to somebody or whatever, and I can really hear the whine with the engine. It's almost embarrassing when people who know I've spent ~$2000 on my stereo system get in the car and hear that crap.

You're right about Don saying the whole RCA/power thing is a myth. BUT, I have seen him say "as long as you have a good set of shielded RCAs." So if you have cheap-o RCAs, maybe that's the problem?

seventy5impala - Do you have good RCAs or are they cheap like mine?

 

i got some 'ok' rcas...and no noise for me. i also don't have a dedicated power line going to my HU...and using the one off the harness.

 

Give it a try. Change out your RCA's. Something is causing the ground loop. What amps are you running again? It sounds like you have isolated a possible cause. I have 0 whine. Where did you ground the amps? Sorry if you have answered those before. May help get a direction.

 

Well im not 100% sure... I use Stinger Hyper Series RCAs(not sure how they rank) they are a bit long tho, not sure if that might play a part, i got them coiled a little under my floor. im installing a new headunit here soon, just as soon as it gets here, see if its not perhaps my kenwood....who knows.

 

seventy5impala, not sure if you saw the post kpr10is made, but I bet he could help solve that issue. PM him and see if he would take a look at it next time he is in the area.

 

The Stinger Hypers are fine, I use them for most of my typical installs.

Try running a ground lead Directly from your HU to where your amps are grounded. Just a trial wire, no need to hide/tuck/etc just hang it over the seats and all. See if that helps.

 

i know ive said this before, i don't mean to sound like a broken record, but what kind of amp is it? when i had whine, it was the amp...some amps are really sensitive to grounds, some just suck when used for high frequencies i guess. I switched amps, and the whine dissapeared.

 

He has an Arc 400.4, its definately not his amp...

 

i run a kicker 650.4 wasnt a problem in my other car with this amp...dunno if thats something that can start too happin or not..

 

Could be a bad HU. Try another radio if you can. How did you adjust the amp gains? Does the whining go away if you turn your amp gains all the way down? Try using a meter to match the HU output to the amp input.

 

alrighty, then good luck

 

My RCA's were too long also and I had some really noticeable whine. I changed these out (they were UTP rca's btw) with some cheap shielded rca's that were much shorter and my whine was nearly eliminated. I don't know why that is or anything but just FYI, having a small coil of extra RCA's sitting on my trunk floor seemed to induce noise into the system. It still isn't totally gone but you have to turn the h/u all the way down and rev the engine to hear it at all now.

 

engine whine is an input related issue that stems early in the signal chain, mostly due to poor grounds- either a bad HU ground or even a not so strong battery ground can cause alternator whine(thats why the big 3 is so highly recommended)

http://www.crutchfieldadvisor.com/S-...car/noise.html

http://www.crutchfieldadvisor.com/S-..._diagnose.html

http://www.crutchfieldadvisor.com/S-...de.html?page=2

 

DON....how about putting those in a sticky....????

 

I have the same prob also when your turn the music to a certian point off course you wont hear it but still its annoying , Me and my freind ruled out my amps/rca's/amps grounds i got no idea what else it can be do those ground loop noise supressors work?

 

Wow, thanks for all the responses, guys!

I guess I've got a few things to try now. The first thing I'll do (when I get a chance, probably not until Saturday) is take out the HU again and instead of disconnecting the RCAs at the amp itself, disconnect them at the HU and use an adapter to hook my mp3 player up to that end of them. If I have whine then, I guess it's gotta be the RCAs. If not, it's got to be the HU.

If it does turn out to be the HU, I'll try what Don suggested. If that doesn't resolve it, I'm going to have to start screwing around under the hood I guess.

Thanks again and keep 'em comin!

(BTW- Don, you owe me a PM, if you don't mind. )

 

Alright guys, here's my follow-up.

I spent some time on the system today. I ran a dedicated power wire from the battery directly to the HU, and I moved the fuse and holder that came with the Alpine into the engine compartment. I then ran a ground wire from my grounding point in the trunk all the way back to the HU. I then used a battery terminal brush to clean off the male and female adapters on both the positive and negative battery terminals. Then I sprayed some anti-corrosion crap on the terminals.

NO LUCK! I still have the whine in the speakers! What I did find out, though, is that it's ONLY coming through the front speakers. And when I hook my mp3 player up to the end of the front RCAs at the stereo, I get NO noise. So for some reason, the stereo is putting out noise only through the front speakers.

Another interesting I wanted to mention; do any of you guys have alternators that whistle pretty loudly from outside the car? Maybe that has something to do with the whine I'm getting in the speakers? Maybe I need a new alt.?

I really don't know what the deal could be, but I've tried pretty much everything short of replacing batt or alt. Any more help would be appreciated.

Thanks,
Brian

 

Oh and just too toss this in, since he had no luck....i swapped out my old head unit and yet the noise remains....but i think its a little bit less....perhaps thats just me telling myself that in the car "oh yea its not as bad as it was" just to make myself feel better...

 

if its not your hu ground, its your battery connections or failed diodes in your alternator...
"Circuit causes:

Alternator whine can be caused by poor electrical connections, especially at the battery. Voltage ripple cannot occur in a zero impedance electrical circuit. Impedance is simply the amount of resistance to high frequency current. It is analogous to DC resistance and like DC resistance is measured in ohms. The low impedance of the battery holds the aircraft's electrical circuit at a DC potential. Any voltage ripple in the bus is absorbed by the battery. Thus, the aircraft battery acts as a large ripple voltage absorber. Alternator noise cannot occur if the electrical connections have zero impedance. Unfortunately will always be some impedance and ripple voltage in the electrical circuit but the better the electrical connections the less there will be.

Lets assume that the battery positive terminal is corroded. Although DC resistance as measured with an ohm meter may still be low, the high frequency resistance may be very high. The higher this resistance, the greater the amount of voltage ripple on the bus and the greater the radio whine.

Circuit impedance can be lowered by making sure the battery posts are clean and making good contact. Resistance should be less than .01 ohm. Also check the alternator ground connections. DC resistance between the alternator and the negative post of the battery terminal should be as low as possible.

The ideal low-noise circuit would have the alternator power output going directly to the battery's positive terminal. This dumps voltage ripple into the battery. The radio power lead would also go directly to a pure DC source, the battery.

If the alternator power lead and the radio power lead connects to a bus, then voltage ripple can go from the alternator to the radio power lead. The amount of voltage ripple at the bus depends upon the impedance between the bus and the battery. This impedance is higher than at the battery. Thus, in the ideal low-noise circuit, power termination occur at the battery. Power return (ground path) would be wired directly back to the negative post of the battery. This prevents conducting high frequency currents through the aircraft airframe.

With less than ideal circuits, the return path is from the alternator to the engine, engine mount, fireball, and through the fuselage to the battery. These connections should have low resistance. Flat braided ground straps are ideal for grounding the airframe to the engine mount. Flat braided straps are used because impedance is less with a braided, flat conductor than a round wire conductor. "
http://www.sacskyranch.com/altnoise.htm


^^^^^BIG THREE!!!!!!

 

My alternator makes some noise too from the outside of the car. When I was having alternator whine through my system I was thinking the same thing you are....there must be a bad diode in the alternator or something. It was the amp all along. I haven't read this entire thread so I don't know if you have tried a different amp yet but if you haven't I would suggest it. In fact, you should try to replace each component in the chain one at a time to see if you have some bad equipment. I was about to tear my hair out at one point and I swear that I read every web page that deals with alternator whine and nothing that I tried solved it.....until I swapped amps.

 

How does that make any sense over spending a few bucks on wire first?
Considering its something highly recommended for aftermarket systems.
As the article above states(and this is coming from aerocraft info) The battery to ground, chassis to ground and power lead to the battery HAVE to be low resistance. If one is running 1/0 ga as power wire, the same size wire should be used for all those others.

BigDu...are you still running 4ga to those two big amps?

 

he's using an arc amp...doubt it's the cause.

 

Guys ... I like Arc stuff too, but there is such a thing as a bad Arc amp. All equipment goes bad eventually - even Arc.

That said, if he hooked up his mp3 player and got no whine, that tells me it's the headunit. Could be a cold solder joint inside the headunit or just a bad internal ground. Could also be a problem with the RCAs coming out of the headunit. Basically, if you change sources and your whine goes away, it's likely the source unit.

 

OK, I didn't mean replace per se....just temporarily hook up a different unit. The ground wire coming off the battery on maximas is a 4gauge wire which should be sufficient. Im not an expert but I would be very suprised if doing "big three" solved anyones alternator noise problem in our cars. It also costs more than you are alluding to because of the fuses that are needed on those wires that you run when you do the big 3. Large agu fuses+holders+large wire can add up.

 

Dood ... go to home depot ... you can get 1/0 pretty damned cheap and it's all copper. I replaced the big 3 on my '98 and it couldn't have cost me more than $10

 

Thanks guys.

When I had the HU hooked up to the factor speakers several months back (before I installed any new speakers and amps), I don't recall having any alt. whine in the speakers. So I guess it has something to do with the amps. BUT, when I try with my mp3 player, there is no noise.

Manny - I still have 4 awg running back to the dist block, and then 8 to each amp (only 2 feet or so of 8). I know I should have 1/0 going back there, and I will some day, just not sure if I have any time to do it soon.

I did think about this some today at work, and I realized that I never tried disconnecting the RCAs from the 1000.2T. I'm going to try disconnecting those and see if the whine goes away.

-Brian

 

not bustin' your ballz.....but how do you plan on diagnosing a problem and dealing with it when your install is hurting? You have 8ga running to a 1kw rms amp that specifically asks for 4ga. Ever suck ice cream through a straw? Thats high resistance in a high current demand situation. That strain is then passed onto the battery and charging system.
The amps are the last place you look at as a far as the culprit for alt. whine, but in your situation- you dont even have them installed correctly, so who knows. I would look into properly setting up everything before jumping to conclusions.

 

Yeah, I know, I've been meaning to upgrade for a while. But I didn't think this would cause alt. whine.

 

i gave up on getting rid of my whine. its very quiet now...sometimes itll go away. i noticed if i turn the climate controll off it goes away even more. not sure what that would have to do with it.