Horrible Alternator Whine - Please Help!

[Str8Dwn]

Horrible Alternator Whine - Now solved

I think have isolated the source of the whine to the power and ground for my Hifonics ZX6400. I used Lightning Audio 4ga for power and ground (ground is ~12-14 in long and bolted to one of the rear seat bolts after grinding the paint off the body for a solid connection). Whine still exists with no RCAs plugged into the amp.

I called Hifonics and they say their amp is not faulty, and it still whines when the amp is off, so I am likely to beleive them for now anyway. They say I need a Line Filter or I should install a 1 farad cap (not in my budget).

Any ideas? Where would I find a Line Filter? No I can find sells them. I have to turn my system up to drown out the whine on the highway it is so bad.

-Ryan

 

[Str8Dwn]

After even further sleuthing, I discovered that the crossover for my left side separates was too close to the fuse block in the driver's side kick panel. I tried moving it to several different locations (as far away as feasible for tonight anyway) and ta-dah! No more noise. I thought it was my power wire which runs near there, but even putting the crossover right up to it caused no noise. I guess there is something in that kick panel that emits noise.

I also found this article which might be helpful for others with noise problems:
http://www.termpro.com/articles/noise.html

 

[akhilleus]

Be wary of that driver side fuse box... i had a turn on lead run near it and one day i lost power!!??? I check my lines and the turn on lead, next to the fuse box, is MELTED into two pieces that had been conducting though the metal until they broke... Apparently there is alot of power going through there.

 

[chuyler1]

I've never heard of the crossovers picking up noise like that. Good thing to know.

That link you posted seems to contradict itself. First he says that the only place you should use the chassis ground is for the head unit. That would mean that he suggests running the amp ground wires all the way to the battery? Well very few people do that but ok fine. Then he goes on to say that the amplifier grounds should be a short as possible (I agree but it doesn't agree with his previous rule). Furthermore, he says that grounding two amps to the same place can introduce noise even though he stated before that the fewer ground points there are the better. I have always been told to choose a single chassis ground point and ground all amps and signal processors to it.

Everything else on the page is dead on with my experiences. Good link other than some of his contradictary comments.

 

[1sty]

Yep, fuse boxes are about the noisiest point of the car. Aviod putting anything near them. A remote wire should be fine, for one to melt seems to be an entirely different issue.

If at all possible, run RCA's on the other side of the car from the fuse box. Or atleast away from it. In Civics and such where the fuse box is under the dash, its usualy so long as the RCAs are on the floor.

 

[nictlg7]

I have the alternator whine as well. I have been diagnosing it for weeks, and I am about to give up and rip everything out! I think I have a ground loop, because the whine gets louder when you rev the engine. It only happens with the car started, from what I can tell. What I have in the car is as follows:

Stock receiver with Sirius radio hooked up (under passenger seat)
Grounding kit in engine (if it may contribute to ground loop?)
4 gauge wire running from Stinger battery terminals along drivers side to trunk
into a Stinger HPM series fused ground/power distribution block
8 gauge wire running from distribution block to 1 4 channel MTX amp
(I wanted to be able to run to my stock Kenwood amp and/or MTX 2 channel amp if I ever run all of the speakers off the 4-channel and save the 2-channel for the subwoofer, or if I run the stock subwoofer along with my Infinity)
out of the 4-channel amp is 12 gauge twisted wiring running to two Kenwood eXcelon series crossovers that run to the components: 5 1/4 mid and tweeters - Please note amp, then distribution block, then crossovers are all mounted next to each other in that order in a custom carpeted box)
For signal wires, I have Rockford Fosgate twisted RCA cables, and I have tested with the stock cheap RCA wire as well)
Also, tonight I disconnected the stock wiring. I found the crazy harness they use on the drivers side behind the back seat in the trunk, and disconnected it. I also clipped the wire when I ran the power wires into the battery terminal, and I disconnected the stock amps ground, which was the bolt I used for my ground wire. Oh yeah, the ground wire is only about 2 feet long, running from that custom box, under the back seat supports, over to the drivers side rear seat bracket, where I mounted it with a huge Rockford Fosgate 4 gauge ring terminal. It has been mounted to bare metal, as well as the seat bracket with paint scraped away for a good contact, with no change to the noise. If you disconnect the RCA for the components, you don't hear any noise in the subwoofer, but perhaps it can't pick up that high a frequency? If you connect only the components, or the components with the subwoofer, the sound is the same. It changes slightly depending on which wire you use and which output (front/rear/non-fading) you choose, but it is not a very noticeable change. I don't know where else to go with this unless I should ground it off above the factory amp rack. Someone on here suggested that in a thread I read. Does the cross-overs being next to the distribution block and power/ground wires have anything to do with this? I have better 16/12 gauge twisted wire and another twisted RCA cable from Fosgate on the way to help cancel the noise, but I am not sure if that will resolve the issue. I am thinking...not! Where might my ground loop be coming from? Anyone in Southern Cali who can fix it, I have cash!! Hah...thanks in advance for any help anyone can provide, thank you!

 

[chuyler1]

Sounds like you're doing everything right so far.

Disconnect all the speaker wires from the amp. Grab a house speaker, or pc speaker and connect it directly to the amp and have a listen. If you still hear the noise coming from it, you can rule out the crossovers or speaker wire. If the noise goes away, reconnect one of the original wires and connect the pc speaker to the crossover outputs. If the noise doesn't come back you are probably running the speaker wire too close to the fuse box or there is a short in it. If the noise does come back, then your crossovers are too close to your amps and distribution blocks.

If none of those tests succeeded, I would disconnect your grounding kit to see if that is introducing noise.

 

[akhilleus]

Another possibility is an exposed rca terminals or other harness wires... i have had it happen to me on occasion... not anymore though. I think it came through my rcainput->rca&1/8" setup.... but i fixed that since it was a bad rca that was causing other problems as well.