I was wondering if there is such a thing as a 50A filter that I could hook up to my Amp. to get rid of the alternator noise I currently have in my speakers? I have regrounded the amp numerous times, and where it is currently grounded is about as good as possible at least it has minimal noise associated with grounding problems, and RCA cables are too far away now to have current induced into them. This is the only fix I can think of currently. Any other ideas would be great, as I am just tired of this noise.

BTW, if anyone needs to know, the Amp I am working with is a PPI PC4400 that is running 8-gague wire from the battery with a 50A inline fuse. It is grounded between the chassis and the rear metal plate behind the passenger seat. I made sure that there is not paint between the connection.

 

Ok, now fiddling with the stereo a little more, I have narrowed it down to just alternator whine from the right front speaker only. . . If I switch the RCA's it disappears completely from the car. . . When i switch it back, the noise comes back. . . Any ideas of what this could be?

 

I am sick of the noise. I tried all the same things you did, plus I even got an aftermarket higher output amp. Nothing worked. I have all the wires, power and signal cables seperated on either side of the vehicle, redid all the grounds, even trying to move the grounds at a further locations to eliminate ground loop. I then put a noise reducer to the stereo itself, which helped eliminate the wine about 30%. I was wondering the same thing as you. I am going to a local stereo shop to see if they have large noise surpressurs to add into the power wire. I have 4 awg leading back to a distrubution block, then out to two 8 awg wires.

Strangly I noticed that the noise increases about 2X when I have my cellular phone car charger plugged in.

It is not that bad, and I can't hear it unless I am accelerating hard between songs, or the volume is way low. It just bothers me that I spent over $3000 in my stereo and I got this damn noise at all. I'll drop you an email if I can find a large guage or amperage noise surpressor. I need one that is at least 60 amps to 80 amps.

One last strange thing is that when I pull the stereo out of my dash and place it on the seat next to me, the noise is gone. That is as wierd as the cell cord making more noise. I wonder if somewhere inside the dash, some of the wires are causing a ground loop. Oh besides, alternator whine can be in all your speakers, or sometimes on one channel and not the other!

 

I had problem with alternator whine in my last car.
Here are my suggestions:
- make sure the amp is gounded (remove all the paint from the chasis and use a star washer)
- make sure the RCA cables are away from any power wires (even the amp power wire)
- Try regrounding the head unit
- Depending on current draw (you can increase the size of the ground wire on the battery and the alternator)
- Try a different pair of RCA cables or buy a pair of high quality intertwisted RCA cables (they reduce noise between RCA cables).

My problem was that I was running my RCAs too close to a power wire and also one of the heads of the RCA cables was pinched. I replaced the RCA cables and ran them on the opposite site of the car. No more noise.

Bryan
1997 SE - not stock anymore

 

I have redone the ground about 5 times now, all in what I would consider really good places, so I doubt that i it currently. I took apart the dash last night and checked everything to make sure it was plugged in and stuff and nothing was crimped or anything like that. I didn't try to see if it still whined with the deck pulled away from the dash. . . I may have to try that.

My question is how would I reground the head unit? What would this take and how easy is it? I know enough about the stereo, but I don't want to screw things up back there. . .

The other thing I was thinking that may work, although it is expensive and probably not a good idea, is to get 3 20A filters and wire them in Parallel with a 50A (Or 60A would also work you would have to get a 4th to make it work with 80A) inline fuse. This should be capable of handling 60A total, And should be able to filter stuff. This would get expensive though, so I am reluctant to do it for noise that is only annoying when I have the AC on it's lowest setting and the stereo turned down low. When I ask my installers about it, they said everyone with that amount of power has some noise, but I don't believe them as I didn't have it before they redid my trunk. Also, My system is only pulling 400W total, it could go as high as 800W if I did the resistances different in the speakers, but I don't think I have enough power to be causing this amount of noise.

 

I used to work for an install shop, and have always found Nissans to be a ***** with wiring! I have had systems that range between 300 watts to 3000 watts in my old show truck, and have never ran across alternator whine before. It cost me $100 for this new damn alternator that made no difference, except that now I can add more power items with no problems. I again checked and found that no noise came from the system when the deck was pulled out, but as soon as I started putting it closer to the dash, walla, the noise. So now I don't think that it is any crimping of the wire, and I have all really expensive Monster Cable high performance, No noise RCAs. I need to find a way to reground the stereo also. From my previous knowledge, the whine will always come through the output of the stereo head unit, but in my manuals, they recommend adding noise surpressors into the power lines to the amps, if alternator whine is heard!

 

Before you guys go dump $200 into power filters, try a $20 ground loop isolator on your RCA cables between the head unit and your amp(s).

regrounding the head would also be a good idea. the stock wiring harness ground usually sucks, if it's there at all. the 3rd gen OEM heads ground through the antenna, not the wiring.

as for procedure, it's easy.
grab 4-6 ft of 16-18awg ground wire, pull your head unit out, cut the ground connection off the wiring harness and connect the 6ft wire. now find a spot on your car that you can ground it to (I used a screw off my shifter mounting brackets).. trim the ground wire to the correct length, put an eyelet thingy on the end of the wire and connect. you're done.
it takes about 10 min and MIGHT solve your problem.

since adidas_boy sais that if he switches RCAs and the noise goes away, I would suspect bad grounds ont he RCAs themselves. I used to get really bad noise, and when I chopped the connectors off my RCAs and resoldered new ones, the problem went away. upon dissecting the ends, I found that the ground was either poorly soldered, nonexistant, or the center conductor was frayed and touching ground.
BTW, this was on a set of Esoteric Audio Musica 500 cables. (They're about $80 each- NOT cheap cables)

there's a couple bones to chew on. if those don't work lemme know and I'll give you a few more ideas.

 

What kind of alternator did you get? Did you have to do any re-wiring? Do you have links to the bad boy?

Del

 

Ok, I have tried regrounding the head unit, and trying the ground loop isolator. . . After using the isolator, I think I have figured out the problem is with the RCA cable. When I hook up the isolator, the speaker either doesn't work, or the tweeter put out closer to no sound at all (This happens when I connect that RCA plug in any input on the amp with the isolator on). . . So the next question is do I have to get a new RCA cable, or can something be done to save the current one?

 

Ok, I really don't have any idea what is wrong with everything now. . . The whine has now steadily grown worse. When I remove the front RCA cables from the amp., there is a really bad noise that comes from the rear speakers (this one sounds like a grounding problem) but it goes away if the front RCAs are put back in. The same thing doesn't happen, though, if the rear RCAs are taken out. This problem is new, and I haven't experienced it before. Anybody have any ideas? Could it still be an RCA problem, or is it the head unit or the amp? Each were installed by different people and so I kinda want to get an idea of who I should take it back to. Thanks in advance.

 

that a loose antenna ground may be the cause of the problem. I have this same problem too, but I haven't had a chance to try that.

 

Ok first off I'm not a stereo installer. However I've done a few shade tree installs. From my limited experience the filters don't work, they just make the noise less as someone above pointed out. The problem is with the wiring somewhere, just gotta find it. That's the annoying part.

Try this... Pull out the deck and hold it in you hand. Take some new RCA's plug them into the deck and lay them across the seats to the amp. Now how does it sound?

If it sounds the same then your orginal RCA's aren't the problem. The problem is perhaps antenna, (as mentioned above, unplug it) or grounding.

If the noise is magically gone then the problem is either the orginal RCA's or perhaps their routing.

So are we having fun yet?

Wizeguy

 

I got the alternator from Checkers, it is a rebuild, higher output unit. It just has more pure cooper strands and wraps in it. When you compare this too the original it looks like they stuffed more wire into it!

I didn't keep the box, so I do not know what brand or company makes it, I just asked the guy at checkers and he pulled it out for me. I remeber on the box, that it putts out 35 more amps than the reqular unit. Cost $98, exact replacement fit! I noticed that my lights when at night and the car idling, they would dim a little until you reved the motor. Now they are fully bright at even 500 idling rpms, and I did notice that my stereo seemed to gain a little volume, with no adjustments. This thing is great for you guys if you have like strobes or body lighting or a kick *** stereo. It puts out full amperage at idle compared to about 70% of the stock alternator!

Oh yeah, you gotta give them back your alternator or its $35 more!

 

I finally got to pissed off, trying to figure it myself, and took it to a place called Audio Excellence out here in Vegas. It took them one hour, and they charged me $45. The installer told me that they always have problems with the Nissans with alternator whine. He said since all the controls are electric on the Maximas and Altimas, and Newer Pathfinders, that we get signal carry over that gets into the ground. Out dash gauges recieve electric signals that tell it what to say, and that Nissan does universal grounds, grounding everything to one spot. He then cut the original ground and capped the wire, then grounded my unit to the metal in the dash. Second to help eliminate Signal loss from all the controls, which gives us interference, he grounded the head unit casing to the dash, then made a cooper box to install the stereo in the dash. He said the cooper box acts like a shield to eliminate interference noises. He said that he found this out, because Eclipse stereos now makes all their casings out of cooper to help elimate interference noises. the alternator whine is GONE!!!

I hope this works for you

 

For those of you who might care. . . I replaced the RCA cable that I thought was bad, and now I barely have any noise left in the system. . . I have to turn in just about everything and turn the volume all the way down to hear any noise now, so i think i can live with this.

If I get the time, I may try the idea of adding a copper box to eliminate interferance (sp?) but I have been dealing with this for the past couple of months, and I don't want to mess with anything that I am comfortable enough with. Thanks for the idea though.

 

ok i have the same problem but im not using any rca cables im using the speaker level imputs on the amp so its not the rca cables here could it be the power on wire for the amp the one that hooks up from the amp to the acc power for the stereo in the dash??

 

No, but RFI could easily enter through the speaker wires at the speaker level inputs. I noticed at least one person on this thread is using 8 gauge cable for several hundred watts. If you repair this problem on both positive and negative amp wires you may notice your noise disapear completely.

 

Don't think that would be your problem.
Cause the power on switch just turns the amp on and off, that's it.

Is your Amp properly grounded? Is it in contact with Bare metal? Make sure you use a star head to ground the amp, sand away at the metal to remove the overcoating, and keep the ground wire less then 18 inches.

 

in the trunk there is two big gold bolts with washers on either side of where the spare goes i have the amp grounded to one side and the speakers to the other

 

You have the speakers grounded to the body?
The speakers should be hooked up to speaker outputs of the amp only, they do not need the body ground to complete the circuit. Hook them to the positive and negative speaker wires from the amp.

Also, you might want to check the amp ground. If you are not touching bare metal that could be a problem. Their might be a coating on those bolts and washers that isn't letting your get a good ground. Try regrounding it somewhere else, and make sure to scrap away the metal coating to expose the bare metal.

Also jmax might be right. If your power wires are close to the speaker level inputs they could be causing interference. Try to seperate them as much as possible. Some people Zip tie all their wires together, that's not always a good idea.

 

im talking about the speaker level imputs im not using rca so im using the speaker level imputs there 4 white wires and 4 grey wires and one black wire that in the book says its for a ground if i dont use it none of the speakers work?

 

Oh ok, I see.
Yeah that needs a good ground also. I would go around and recheck the grounds, and make sure the power wires are not near the speaker level inputs.

 

would bad ground cause the surge in the sound to go up when you step on the gas? cuz when the engine is not running it sounds perfect

 

Well since it is alternator whine and the alternator doesn't run without the engine . . .

A bad ground means that you have a ****ty connection or wiring on the negative side, basically. The negative wiring needs to be as good or better than the positive wiring.

 

what i was thinking to see if it was either interference with the power wire or the ground wires was to take a battery and hook it up behind the trunk so that way im sure its not the power wire and if the wine is gone then i know its where i have the power wire routed, would that work?