# Head unit just fried :( Why?



## evildude88 (Aug 11, 2011)

Hi there everyone,

Unfortunately for me my pioneer head unit just fried. I have a feeling it's something that should be able to be figured out, something I missed or something of that nature.

Anyhow, here is what I have.

Car: 2000 Chevy Impala LS (3.8l)
Audio System:
HU: Pioneer DEHP800PRS
Amps: Alpine MRPM2000 and JL 300/4v2
Sub: Orion HCCA 10.4
Speakers: Fronts JLC5650 Rears Stock
Electrical System:
180 amp H/O alternator
D34/78 Yellowtop Optima Battery
NO big 3 upgrade (is this the culprit??)

I have 0 gauge running to the rear, into a fused distribution block (a 150A fuse and 250A fuse respectively) with 4 gauge running into the power on both amps. Both are grounded separately from each other.

Basically what happened is after putting in the JL 300/4v2, with the new speakers, and also after putting in the high output alternator and I turned the volume on the deck to max (for a moment, to set the gains) the deck started smoking and fried! My amps and everything shut off as well. I had the gains on both amplifiers set to 0.

What I think is the new high output alternator fried the deck, because all I did was slapped in the new alternator without changing any of the wires or anything like that. I'm wondering if this is what fried the head unit.

My other scenario is that the head unit itself was just in bad shape and fried, but I doubt that because before I put in the second amp, speakers and the new alternator it worked just fine. What I am concerned with is if I install a new head unit, will it fry that one too?

So my guess is that because I didn't upgrade the wires for the alternator and battery that the head unit received to large of a load and fried. No fuses fried, I checked that.

If someone out there has a clue I would be very appreciative. This really sucks 

Thanks so much.

-Jeffrey

Edit:

I want to add, when installing it the way I installed the fused distribution block was I put the fuses in the block, screwed them in and connected the wires.. then I bolted the block down, and connected the wires to the amps. Is this a problem?


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## RongGe (Oct 25, 2010)

Can you define fried?
Is fried when a headunit catches on fire? Or did it started to smoke and the cabin smells like burnt components?
Did you open up the headunit to see what fried?
Did you measure the voltage with the engine off, on, and on with revving to make sure your new alternator is working properly?



> "I want to add, when installing it the way I installed the fused distribution block was I put the fuses in the block, screwed them in and connected the wires.. then I bolted the block down, and connected the wires to the amps. Is this a problem? "


Can you clarify?


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## evildude88 (Aug 11, 2011)

RongGe, thanks for your response.

1 - Yes, what I mean is the unit started to smoke. It smelled like burnt components.

2 - I didn't open it, because I'm afraid of voiding warranty. I'd like to get it fixed if I can..

3 - That I did not do.  I should have definitely done that..

4 - When I put in the fused distribution block for the two amplifiers, basically the way I installed it was I put the fuses inside the block, put the block in the car and then wired it up to the amps. Basically I've heard you should put the fuses in after you wire up to the amps. So, I'm wondering if doing it in the other order affected anything in this case.

Also no sound came out of the rear speakers, which were hooked up to the deck.. could be a settings issue but when it hit max volume a weird popping noise did come out of them. Front speakers were definitely not working, I'm thinking that's the amp itself.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

evildude88 said:


> Hi there everyone,
> 
> Unfortunately for me my pioneer head unit just fried. I have a feeling it's something that should be able to be figured out, something I missed or something of that nature.
> 
> ...



Everything you've said, says you have a bad AMP... Think about what you've said and what I've outlined....


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## Bluliner (May 16, 2011)

Aaron'z 2.5RS/WRX said:


> Everything you've said, says you have a bad AMP... Think about what you've said and what I've outlined....


Amps don't typically throw current upstream through the RCA's and fry a HU. And when I say typically, it just means I've never heard of it before. 

My best guess to what probably happened is an uncapped speaker lead touched another or were inadvertently grounded to the chassis while the IC in the HU was being clipped into a coma. Kaboom!

A bad voltage regulator in an alternator would do other spooky **** and blow up things worth a lot more than a Pioneer HU. The dash lights would glow brightly and then dim and every other accessory in the car would behave differently. 

Speakers, an amp, and an alternator were installed into the car while the HU was removed and RCAs were possibly added. Lots of stuff was messed with. I'd go through the install again and look for something you overlooked when everything was getting buttoned up. An amp frying a HU is a new one for me and the symptoms of a bad voltage regulator are different.


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## MyJeepGoesBoom (Jun 6, 2011)

Bluliner said:


> My best guess to what probably happened is an uncapped speaker lead touched another or were inadvertently grounded to the chassis while the IC in the HU was being clipped into a coma. Kaboom!


I would 2nd that. Has to be some sort of a crossed wire. Changing your alternator would mess with alot more than just your HU. Have you pulled your deck out and checked to see if maybe you just blew it'd fuse? Might be too simple, and I don't want to insult your intelligence, but I've blown a few fuses and they smelled pretty funky sometimes.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Bluliner said:


> Amps don't typically throw current upstream through the RCA's and fry a HU. And when I say typically, it just means I've never heard of it before.
> 
> My best guess to what probably happened is an uncapped speaker lead touched another or were inadvertently grounded to the chassis while the IC in the HU was being clipped into a coma. Kaboom!
> 
> ...













Obviously amps don't typically don't do that, BUT the fact remains that the HU AND SPEAKERS where working prior to the amp install... 

So please... 

If the voltage regulator on the alt was THAT bad, it wouldn't have been just the HU that fried...Which is EASY to test... 

What sort of voltage do you get at idle? The voltage goes up with RPM to a point, if the reg was shot at IDLE, it would have smoked the CAR at SPEED...


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