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Discussion Starter · #1 ·
OK, we've kicked this horse around enough -so why not start another thread on MY currant headache...

Vehicle: 01 Chevy Silverado Extra Cab
Head unit: Pioneer 880 PRS (active 2way front stage)
Amp: eD Nine.5 (mounted on back wall, mdf backboard screwed through wall, grounded and powered with 0 gauge, ground is solid -through the floor to the frame rail, shiny metal and a BIG bolt)

When my system was powered for the very first time, there was NO noise. Then, after a restarting of the engine after a short trip, ALT whine on left tweeter. :mad:
After about 9 months of torture, I decided to change RCA's and check for a blown Pico fuse...

I disconnected battery, pulled HU, DMM'd the RCA outs with a Diode test (checked out fine, triple 0's -Pico fuse OK).
I hook the HU up again, but left it out with hookups exposed and on top of the dash (then reconnected battery)... After starting and powering up I grabbed some 12 gauge wire, and tried to ground each RCA to the HU chassis... ALT WHINE STILL there NO Change... I then reach to disconnect suspect RCA cable (remembering NOT to "hot swap" them on a Pioneer)... BINGO!... Tweeter disconnected, ALT noise gone!

I disconnect the battery, run a new RCA cable, hook everything back up leaving battery last... Powered up... ALT noise GONE!... But only to return while driving down the road, this time on the right woofer (def. less annoying than the tweet screaming at me)...
NO problem, just change that set of RCA's, right?...
Wrong:mad:, I go through the same process over the weekend, now being an expert at changing RCA's, powered up... ALT whine RETURNS... This time on the RIGHT TWEETER!... It has MOVED to different channel ever time I've changed new RCA's... This is NOT me hooking up the RCA's backwards, or getting them in the wrong spot!

So I pull the HU... AGAIN :mad:... This time I pull the RCA Preout Plug from the back of the HU... Left the power plug in (So NO sound is being sent to the amp by the HU)... Powered up, amp comes on, ALT noise STILL on the RIGHT tweeter! :confused:

SO NOW, I'm in the process of grounding EVERYTHING!... But since the AMP has now shown to be the noise, I need to start there first...
Dedicated ground wire from battery to the frame?
I've got a pretty long run to where the amp is grounded (since it's on the back wall)... And I don't have anymore 0 gauge wire handy.

Suggestions/a little hand holding here?... How close do I need the dedicated ground wire to the amp ground? Same bolt?
Any theory on how and why my amp has moved the noise to different channels?
 

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I don't have a theory regarding why the noise changes channels, but I do believe your troubleshooting reveals the amp to be the problem.

I personally feel that the amp ground chosen is more important then the length of ground run...uncommom, but its just my opinion.

With that said, I would choose 3 new potential ground areas, and try them out. There won't be a magic trick to the solotion, only troubleshooting and trying new places. I batteled an alternator whine for 4 months, and it took a 1/0 AND 2 awg ground (from a d block which the amp grounds ran into) in different spots to cure it!
 

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I read it all, but did I miss mention of the big 3?

You may be grounded to the frame, but if your frame ground, up front, is suspect, then you may have an issue??

The amp is definitely suspect now, with the noise moving about with no input
 

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Discussion Starter · #4 ·
I read it all...
Yeah, srry it's a long read -but I wanted to be thorough in showing the steps that I've taken... I also started a new thread hoping it would contribute to more "search" function material...

I'll take a look at my trucks wiring harness, and see if the ground needs to be "enhanced"... It has been replaced and is practically brand new... If nothing changes there, then I'll start adding the Big 3 in stages...
But I was also wondering, could the speaker wires be picking up this noise somewhere along the way?
 

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The one true SQ freak
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You need to try another amp and see if you still get the noise. My gut feeling is it's a failing amp.
 

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I would check the wire to that tweeter also, a short sure can cause the amp to make noise. Providing the amp ground has good contact, you should be able to run a smaller wire battery to frame since I assume the battery is on top of the frame and it would be really short. If you can keep good outdoor connections the frame will carry much more current than any wire.

My 880 has the same thing in right front but pretty sure it is cheap twisted pair RCA doing it. Funny how they worked fine with an alpine HU. Just got a new one need to put it in....this is typical pioneer in my 20yr of messing with it. In fact I swapped the 5ch amp out and no change but did that for other reasons.
 

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My phone suggestions are still the same.

Upgrade factory headunit ground because the stock ground in gm trucks is trash.

Only part of the big 3 I feel is important is the batt negative to frame rail. Taking it to the engine block via the bolts that hold the "red box" under your hood to your alty ground can help too.

Swapping out amps just to see what happens is a great suggestion. Like I told you the other day I could probably find your problem in the matter of a few minutes with the help of a long rca cable to jump from my truck to yours.
 

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Discussion Starter · #8 ·
k, HB... SO... I got cable (4g from auto zn) ... send it to the block stock locatn, or the frame rail?
 

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Take it to the frame rail since the amp is grounded there. If you have enough left over jump over to the block. No need to go from alty to batt positive. Making your whole vehicle a common ground is far more important.
 

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im still a little new to this but one of my amps were touching a screw on my amp rack sending a ground loop(i believe) wine that could be the problem.
 

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Yeah, srry it's a long read -but I wanted to be thorough in showing the steps that I've taken... I also started a new thread hoping it would contribute to more "search" function material...

I'll take a look at my trucks wiring harness, and see if the ground needs to be "enhanced"... It has been replaced and is practically brand new... If nothing changes there, then I'll start adding the Big 3 in stages...
But I was also wondering, could the speaker wires be picking up this noise somewhere along the way?
no problem...

I would try anything right now for tests sake, to re-ground the batt to the frame..

A ground loop is formed when 2 grounds are of different potential, creating a potential difference (exactally what make a battery work, no potential difference, no current)

The key is having all grounds on the same potential, and not all grounds are the same..

I bet 10min with some 4g might fix this..

But I would also have to agree with SQfreak about the failing amp.. won't know till you try the grounding..
 

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Discussion Starter · #12 ·
Well last night I bought 2 runs of 4g at Autozone (pre-made alt cables)... Was goin to to 2 of the Big 3...

Waiting for my cordless drill to charge, and 10 beers later, I had done nothing but clean my truck out to access wires... :rolleyes:
I started moving wires around, checking connects, freeing kinks, etc... Both of my Amp's power and ground cables are a little long BTW, and could use about a foot and a half of trimming...

Story short, I got the noise to almost go away... hopefully from moving **** around, and trimming up some wire, it will clean up.

I did run a dedicated 12g ground (Bat to HU) and nothing changed (as I expected -because I determined te noise was coming from the amp).

I will proceed til the noise is extinquished. I appreciate all of your input. They are all valid solutions.
 

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Somebody else around here almost went batshit insane trying to find problems that were caused by their eD 9.5...cant remember who though...
 

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Yeah, I know the 10 beers later part... they are always empty for some strange reason.. lol..
 

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Somebody else around here almost went batshit insane trying to find problems that were caused by their eD 9.5...cant remember who though...
You know Ben, they make some good pills to fix these eD problems these days..

It's either Prozac or Viagara, not sure which... :D
 

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Discussion Starter · #16 ·
Somebody else around here almost went batshit insane trying to find problems that were caused by their eD 9.5...cant remember who though...
It was ItallianStallion, I think... Way different symptoms... Main prollem was teh power supply.
 

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My alternator noise has cleaned up since I choose a new
ground location in back, used 1/0 for the ground, and used 1/0
from the front battery neg to chassis (big 1 lol).

Maybe you should check your amp ground outputs, maybe one
of the ground wires has some jacket in the input sleeve preventing
good contact. I had that as an issue on my test stand once.
 

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Discussion Starter · #18 ·
MC,
What new amp ground location did you use, and on what vehicle, amp, etc?...
My amp is grounded very well through the floor to the frame rail, on bare shiny metal, with a threaded bolt hole through the frame, then a lock nut on the other side!...
I am going to do the bat neg to frame next... Seems to be the best recomendation from everyone... I will bolt that fkr down as well... I jsut needs some daylight and free time to do it! :rolleyes:

Hopefully by this weekend, I'll have er patch up with some pics.

My amp ground:


Amp placement:


Console:
 

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Discussion Starter · #19 ·
Update...
The alt whine is gone!...after I did a negative battery post to the body ground (under the hood) with 4 gauge alt wire. I used a 32inch run of prefabbed "switch to starter cable" (It was raining so I didn't want to crawl under the wet truck to ground it to frame)... Now that know what's up, I may do that later on a better day for it... Easy fix. Not bad for $7
 
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