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Discussion Starter #1
I've got a simple system going here. A single 12" subwoofer in a box powered by 400w amp. Anytime I turn my subwoofers on(which can be turned off at my Pioneer head unit) I get excessive amounts of engine noise stirctly through the subwoofers. I have a ground connected directly to my frame rail.

I went out and bought a Ground Loop Isolator hoping to remove the engine noise and was unsucessful.

What exactly causes this issue? What are the best ways to eliminate?

I was once told that by installing a Crane Fireball it was causing the issue?
 

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Bad ground. Why did you ground to the frame rail?

Ground it to your body, and check the rest of your body to frame grounds.
 

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Discussion Starter #3
Bad ground. Why did you ground to the frame
I understood that you're supposed Ground electrical to your frame. I had the ground on the body and still had the noise. So I moved the Ground cable to the frame hoping to eliminate the issue. Obviously it hasn't been eliminated even with a Ground Loop Isolator.

I'm at kind of a loss at the moment and have very little electrical knowledge.
 

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Yeah move the ground.

Also are your RCAs and power wire ran down opposite sides of the truck? Running them side by side can introduce noise into the RCA cables therefore outputting them through your subs.
 

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and pioneer has a crap rep when it comes to there outputs. theres a thread over on caraudio.com just for this. u need to ground the female part on the rca on the back of the deck. kinda hard to explane. go over to caraudio.com tho and its all over there.
 

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just because the amp is grounded well does not mean the noise source is grounded well
 

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What they said plus--

Shorten your ground wire as much as possible. A long ground wire will act like an antenna and pick-up noise (under 18" preffered, so says the propellar heads and always fixed my problems).
 

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just because the amp is grounded well does not mean the noise source is grounded well
:stupid

Check your body to frame grounds... you want your amp and head unit to have the same ground potential. You could also take a look at the ground on the back of the head unit, and if need be, put a new one from the case of the unit to the bar in the dash.
 

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It could the the high perf ignition causing your problem. My system had no motor noise at all before I installed the MSD ignition. Once that was installed, the noise was pretty bad. MSD has a capacitor, MSD-8830, that solved the problem for me. Instead of running the power and ground directly to the battery, it goes through the capacitor first. Not sure if Crane offers one but the MSD one should work if not.

Good luck!
 

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Discussion Starter #10
It could the the high perf ignition causing your problem. My system had no motor noise at all before I installed the MSD ignition. Once that was installed, the noise was pretty bad. MSD has a capacitor, MSD-8830, that solved the problem for me. Instead of running the power and ground directly to the battery, it goes through the capacitor first. Not sure if Crane offers one but the MSD one should work if not.

Good luck!
I checked Crane. They don't appear to have a device like that. I'll check out the MSD and see what happens. I've checked grounds, power,....

the power does go down the same side as the RCA's, but the problem did not exist pre Ignition Module install. Or at least,it was way lower.
 

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I checked Crane. They don't appear to have a device like that. I'll check out the MSD and see what happens. I've checked grounds, power,....

the power does go down the same side as the RCA's, but the problem did not exist pre Ignition Module install. Or at least,it was way lower.
Ah, well that explains a lot. You didn't mention that.

There's a small cap even on the stock TFI coil, they can go bad, and will leave you with noise in your system. A dead/dying diode in your alternator, and a bad ground/ground loop will also do it, so yeah, having the little details helps when trying to diagnose across the internets. :thumbup

I would bet you could just pick up a new capacitor from Ford... I don't know what the ratings are on it, or I'd post them and tell you to grab a matching one from Radioshack.

Is your stock one still on there?
 

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Discussion Starter #13
Well, sorry i didn't mention that before, major detail i left out, but let me make clear,...
The issue was there before, but no where near as bad. It's funny u mention the diode in the laternator. At the moment I have another thread mentioning my alternator varying badly in power. I need to get it tested soon. I believe I'm going to step up into the 3G alternator to power my truck. We'll see what happens soon!
 

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Yeah move the ground.

Also are your RCAs and power wire ran down opposite sides of the truck? Running them side by side can introduce noise into the RCA cables therefore outputting them through your subs.
If you ran your rca's and pwr down the same side of the truck youll get a bad humm from them all the time. Will make it not worth having them. Make sure there on different sides. Your ground should be no more then 3 feet. After that it starts loosing its purpuse of being there.
 

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power and rca's on the same side dont matter if u have good rca's. thats y they are sheilded. its more of a mith on that. ive always ran them on the same side with no problems. in some installs u have to run them together. some models of cars have lots of wires ran down one side and u can pick up noise from them thru your rca's. depends on what the wires do. my whole install is under the carpet with everything ran 6inches from each other just to make shure i wont have problems tho. www.caraudio.com go there and i believe its in the general section theres a topic about fixing the problem u have. i would also look into that capaciter on the ignition being blown to. go to the junk yard and grab a few. max cost will be like 10 bucks for a handfull.
 

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and as every one said. a ground shouldnt be more than 3 feet long other wise u start picking up crap thru it like a antenna
 

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power and rca's on the same side dont matter if u have good rca's. thats y they are sheilded. its more of a mith on that.
It's not a myth, just generally over emphasized... what's the best way to do it? Don't run power and RCA's together... Best absolute way to do it? 18v balanced pre-outs.

It takes an extremely good shield to block em/rf interference, 95% of RCAs out there don't have good enough shielding.
 

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and as every one said. a ground shouldnt be more than 3 feet long other wise u start picking up crap thru it like a antenna
And no. Your entire truck is a ground, the wire length doesn't matter.
 

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I've never had an engine noise problem (other than the MSD ignition that was fixed with the MSD capacitor) but I heard once that using a long ground wire and coiling it up before connecting it to the amp will act as a choke and may help filter noise. Again, never tried it, just something I remember from back in the day.
 

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Discussion Starter #20
I'm looking into better set of RCA cables. I've ALWAYS ran my RCA's and Power down the same side and I have NEVER had a noise issue.
Saying that, I am using cheap RCA's now and previously in another vehicle I used better shielded cables from Rockford Fosgate.
I bought the MSD cap. I'll see how that works. It's to damn nasty outside here in northern Cincinnati to work on that damn truck at the moment.
 
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