Upgraded ground...now noise...HELP!!!

[DDFrontier 10+ year member]

Ok, guys and gals, I need some help....

Today, I was bored and decided I would change out the old ground wire from the distro block to the truck body. The wire was turning black and I wanted it to match the new silver RF wire I had on the amps.

Well, I forgot to open the circuit breaker under the hood, soooooo, you know what comes next, the loose ground wire touched a hot wire on the amp and arced for a split second.

I thought, great, I've fried my amp. Well, I get everything all wired back up and I turn on the radio. Everything works fine, but there is this awful whine in the speakers even when the radio is at zero volume. Start the truck, and here comes all this loud alternator whine that I never had before.

I put in another amp temporarily and the noise is just the same. So, then I suspect a bad ground since I had just messed with the ground. I sanded the ring terminal and the grounding point. Still no good. I ran another ground wire from the battery negative to the body. Still no good.

At this point, I'm thinking maybe the voltage went backwards and fried my passive crossovers. Nope. Wired up a spare speaker to the amp, still have that nasty noise.

What the hell is left, the head unit? I checked all the fuses on the harness and everything looks fine. There are two diodes on the 12V+/switched and 12V+/always on wires in the harness. Aren't these there to protect from frying the head unit? They look fine, but maybe they're toast? Every function of the amps, head unit, XM, all work fine. I disconnected the XM module and that made no help, in fact, the noise got louder. I have the head unit grounded to the metal in the dash and when I remove this, the noise gets louder too.

Any idea what I did? I have spent 3 hours unplugging, regrounding, swapping, etc. only to still have the problem.

I have a RF Punch 200.2 and RF Punch 325.1 amp, Pioneer DEH-P6600DVD head unit, Polk Audio 6.5" component set, and two Pioneer 8" subs.

Running 4 gauge power and ground with short runs of 8 guage from distro blocks to amps.

Everything was fine before this arc of electricity, so I highly doubt it's a wiring or equipment problem.

A ground wire touched a constant hot on the amp terminal block. All this did was complete a circuit from the battery 12V+ to the truck body (ground), right? The radio and amps were not even powered up. What harm could this have done?

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[dragonrage 10+ year member]

I know the first thing you did wrong - you posted a thread asking for help without telling us what equipment you have. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[hardhitta47 10+ year member]

try another hu and see what happens.

 

[DDFrontier 10+ year member]

try another hu and see what happens.

Man, that's gonna **** if it's jacked up! This isn't exactly a cheap head unit. Aren't those fuses and resistors there to protect it? What is the large black plastic box with the ground and yellow wire going through it? Is it some type of ground-loop isolator?

 

[hardhitta47 10+ year member]

I'm no expert, but I'm just wondering if when you fucked up maybe the rca's fried something in your hu. Some of those internal "fuses" I've heard are basically hair-line traces on a pcb.

It's about the only thing that's left to try that I can think of though. You've checked your grounds, amp, and xovers, so..?

 

[DDFrontier 10+ year member]

Yea, I'm guessing it needs to go to a Pioneer service center now.//content.invisioncic.com/y282845/emoticons/furious.gif.fc81ca146dbff91fede3ed290dbc4f4c.gif

 

[DDFrontier 10+ year member]

Well, I just grounded the RCA outputs to the HU chassis. 95% of the noise is gone. Should I run the HU ground to the same point as the amp ground?

Maybe the short with the ground wire today somehow blew the ground on the RCAs inside the HU?

 

[jonnybusa 10+ year member]

Man, that's gonna **** if it's jacked up! This isn't exactly a cheap head unit. Aren't those fuses and resistors there to protect it? What is the large black plastic box with the ground and yellow wire going through it? Is it some type of ground-loop isolator?

try grounding directly to the battery to see what happens

 

[spoonraker 10+ year member]

Aren't Pioneer head units notorious for having their internal fuses blow and causing a lot of noise unless you reground it. I know I saw a thread on it somewhere, I thought it was here. I'll see if I can dig it up.

 

[spoonraker 10+ year member]

here's that thread I was talking about, sounds like you already did something similar, but maybe this will help

http://www.caraudio.com/forum/showthread.php?t=198477&highlight=pioneer+rca+ground