Oh god... I effed up something electrical... help.

[bangandow 10+ year member]

I've tried to keep my mouth shut and just read for a while here, but I've come across a problem I really need help on.

Today I cut out some MDF baffles for my door speakers and went to install them on the car. Once installed, I turned it on and this LOUD ******* siren-foghorn sound erupted... so I tried turning volume down and nothing happened, so I turned off the car and it stopped.

I then removed the newly-placed speaker and found that the terminals on the speaker were touching the sheet metal of the door... I guess grounding it to the vehicle.

So I took the speaker out from the door, turned it back on, no more deafening alarm sound... but there's this awful static coming through all the speakers. Loud, obnoxious static. I thought the LOUD noise earlier had blown my speakers, but no.

See, with the key only turned to the first position, it sounds nice and clear... no problems. When I turn the key to the second position, this loud crackling static starts coming on. When I actually turn the engine on, a really bad case of alternator whine is then added to this static. Turning on/off any of the electrical components (lights, a/c, etc.) adjusts the tune and volume of this noise.

So I figured maybe I effed up my alternator, so I went to test with my volt meter. Without the engine on, I get 12.8-13 volts at the battery. With the engine on, I get 14, so I take it this means my alternator's still producing power.

There's this weird almost rubbing kind of sound coming from the alternator that I've never noticed before, though. Faint, but definitely audible. Is it possible I fried something in there and it's introducing noise to the electrical system, but at the same time still producing plenty of power?

Any other ideas?

Please, for the love of god, help... I was just starting to become satisfied with my work thus far //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

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[DeViOuSoNe 10+ year member]

What kind of headunit?

 

[bangandow 10+ year member]

Pioneer DEH-P7800MP

 

[DeViOuSoNe 10+ year member]

Ygpm

 

[enzowho 10+ year member]

You're f-ed up the a!!!

Lol, just kidding. The sound erupting from your speakers was probably due to your amplifier's over-current protection circuitry working. The reason I say that is because my friend did the exact same thing and it sounded the same as what you described. His amp went into protection, but worked fine after that.

I don't understand the cause of the noise afterwards though. Did you install or change anything other then your MDF rings? Did you have any noise before shorting your amplifier (or HU, you didn't specify)? It sounds like a ground loop but I don't know how shorting your amp would cause that. But...check all your grounds and see what's up.

Also, no you didn't damage your alternator.

 

[bangandow 10+ year member]

Everything in the car is run off a kicker amp...

Nothing has been changed except for switching from plastic speaker mounts to MDF baffles.

I had a very slight alternator whine before this, but barely audible. This noise competes with the music though =( I'm just glad it doesn't get louder with the volume knob, only with the rpm's.

 

[maldecido33 10+ year member]

are your speakers off HU power or an external amp?

 

[bangandow 10+ year member]

Everything in the car is run off a kicker amp...

i.e. front components, rear coaxials, and subs.

 

[DeViOuSoNe 10+ year member]

Amp isnt on is first key phase, Which means that the noise is coming on when the amp is. Probally a bad Rca hu ground. Which is most likely the case since its a pioneer. Un hook RCA's from amp. Start car. See what happens. I would bet there is no sound. Which leaves the HU'S rca ground. Which could of got messed up when wires touched.

 

[enzowho 10+ year member]

If you had alternator whine before its a ground loop somewhere. It was aggravated by shorting your amplifier. I would suggest doing a quick forum search to see how others have dealt with ground loops as there are many good threads about it.

But to get you started...

1: Check amplifier ground

2: follow steps found in Deviousone's post

 

[bangandow 10+ year member]

Amp isnt on is first key phase, Which means that the noise is coming on when the amp is. Probally a bad Rca hu ground. Which is most likely the case since its a pioneer. Un hook RCA's from amp. Start car. See what happens. I would bet there is no sound. Which leaves the HU'S rca ground. Which could of got messed up when wires touched.

Amp is turned on in first key phase, though... everything audio-related is turned on and it still sounds crisp and clear, no problems, at the first key phase.

 

[DeViOuSoNe 10+ year member]

Still a hu ground. It isnt picking up all the noises until they come on. Like i said un hook rca;s from amp start car, see if it goes away

 

[bangandow 10+ year member]

If I unhok the amp's RCA's, then there won't be any power going to the speakers anyways, right? So, no matter where the noise is coming from, it'll stop...?

So tomorrow I should take my dash apart and relocate the ground? Maybe move it to the floorpan just beneath the dash instead of the metal bracing in the dash?

 

[DeViOuSoNe 10+ year member]

nope..Unhook them from Headunit ,And then start car..>If it is coming from amp's ground or power wire, it will still be there. And it all depends on how you ahve the amp hooked up. Make sure ground isnt too long as short as possible

 

[bangandow 10+ year member]

Alright, well thanks so much for the help //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif