Speedbump, then out cold-Sub or Amp prbm?

I've had this amazing system running for 2 weeks now, and the other day, I was taking some Chicago speed-bumps pretty hard in my Xterra, and the last one was a doozy. Then, my whole system went out cold.

I don't know if it's the HU, or if the Amp's triggering a shutoff. I really don't know where to start, so I'll provide a list of symptoms, clues and facts, and if you have a diagnosis, please lend me some ideas!

* The Kenwood X979 HU shuts itself off now at random, sometimes after warming up, sometimes right away.

* The reset (pen) button turns it back on, with all settings back to default (lost presets, etc.)

* Amp is a Kicker Impulse 405D (runs 4 + sub)

* The HU runs OK if the Monster-main inline-fuse is disconnected from the battery post. So, it's when the amp is cut off that there is no problem.

* The last test I ran was to get the HU running again (via reset) and quickly shut off the Sub (Alpine Type-R 12" IN BOX) via the sub-off button on the HU. So far it stays on with no Sub activated!

* When it does cut out, the MASK face stays open like the batter was disconnected, until I reset the HU, so there is power going to it. It's as if the HU is experiencing a surge or brief cut in power.

All this tells me is that running music thru the HU from the amp (seemingly only with the sub on) appears to shut off my Head Unit at random. I really hate to think that the HU was affected by the speedbump. It would be more logical to think that the sub is somehow affecting the HU.

How that's possible, I just am not knowledgeable about electronics to understand the relationship between the wiring and the whole component system.

So, if anyone can pinpoint this based on my tests, please help a poor stressed out audiofile out! I'd like to believe that this really is an amazing system I've put together, and that the jolt loosened some wiring somewhere. But the Sub seems to be the only constant culprit here.

Thanks!

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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

first thing I'd do is check every wire connection, including the fuse holder. next thing I would look at is the sub. take the sub off the box and check the wires that run from the cone to the quick connects.

i would check your rca's for your subs, ,they could be grounding out on you, , , thats the only thing i could think of that would effect the deck that way

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

Check them where?
Off the HU, or the Amp?

Someone else in another post mentioned that the Crossovers were lighting up like christmas trees. Mine do too, above the foot cavities, I thought that was normal, until someone in that post said it could be a grounding issue. But they lit up without flaw in sound well before this problem. So it's not related that I can imagine.

The Sub also makes the most sense too, because that big box comes down harder than anything when I take speed bumps!

My Guy is gonna look it over tonight,

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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

the lights are distortion

Which is normal under higher volumes, right?
Or is that telling me to tweek the volume/gain relationship?

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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

thats tellin ya to turn it down, your signal is clipping and damaging your speakers while sounding like crap.  its not cool to have it loud if you can distinguish whats being sang or played.

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

The only other thing I can think of is checking your ground on your head-unit.

OK,

I took the Sub out of the box today. and that Alpine is built like Fort Knox. It can't be that.

Again, I had it smokin' for about 15 minutes today, and fizzz. Out again, no particular reason.

Even with the Sub off (off via head unit button. Holding down AM/Folder - button turns off Sub), I got it to cut out by tapping the dashboard right next to the Head Unit, twice to be sure to be sure.

Soooo, this means that it is surely within the dash environment itself. Best case, a bad ground or hot.
Worst case, a bad head-unit. Which would mean I'd have to get another one, while I send off this one to Kenwood, and get it fixed under warranty.

At least I'll have a backup when the second one goes out!

I don't see how a speedbump can loosen a nut and tape job. But I'm taking it to a pro-shop tomorrow, hopefully they'll take my money to do a diagnosis, since I'll make it known I'm not going to make a purchase.



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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

ask them to solder all the connections and get it over with, , no more connection worries, , , , if it still craps out, , then sender back.

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

all nissans have the crappy ground,, you definately need to ground some metal that connects to the chassis.

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

First off, I just want to say thank you to all who have taken time to give ideas. We all have better things to do, and this is just super, I am lucky to have found this and the Xterra club, and the MacNN, etc.

OK---so my guy blew me off, and I had to do this myself, but I remember watching him install it, and it's really easy. The 4x4 Shifter is the only thing that makes it a pain in the ass (we can swear here, right?)-

Anyway, I took the dash apart and the head unit screws off the mount, and pulled it out. The g****** thing didn't go out once while I had it on the passenger seat!!! Nothing wrong.

So, I tried to yank, and twist, and anything I could to simulate the episode, and nothing. It wasn't until I got it back in the chassis (right term?) in the dash that it went out! If I was Jewish, I could think of a few words to shout.

But I guess I'm relieved to know that it has to be a wiring thing like y'all said, and not the receiver. God, what a sweet sound-processor and interface and everything else about the Kenwood is just magnifique.   

To sum this up, I did notice the black ground from the HU connected to the stock wires, and strangely enough, it actually breaks off into two seperate harnesses! I pulled and they're tight as can be. I repeated the action of placing the HU back in, and it went out like clockwork again. So, I remembered the recent installation of the (get this) 6 meter Keg cable (Keg is a PhatBox with Kenwood name on it) which is crammed in with all the other wires. All the wiring behind the dash is enormous, and must be the culprit. So I pulled it all out and placed it back in again. So far, so good.

Drives me crazy to think which one it could have been, but I think if it happens again, I'll snip the ground, and wrap it around one of the screws like you say.

That's it, and if anyone wants to elaborate on the crappy ground issue, it may be interesting.

Thank you again...
-matt

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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

PS - it was purely taped, not wirenuts!!!

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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

PSS - The crossovers no longer light up, is that a good thing?

And does a more stable ground kill the distortion that was occuring?

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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious

y would the sub being turned on cut the deck out is wut im trying to figure??

This is what I've summed up. Every time I say "everything's great now" I get burned, and Murphy's Law comes back to haunt me. Chicago still is an Irish run town.

I can only assume that the ground solidity was the reason.
I did nothing except jiggle the wires and tug & yank.

Finally it seems to be grounded correctly. If the above mentioning of Nissan's shortcoming is true, than that must be the case.

Maybe the Sub caused enough "sub-sonic" vibration that broke the connection for just a split-second long enough to trigger the shutdown. Maybe the HU itself is protected from surges and connection screw-ups???

Who knows. Like I said, if it happens again, I'll take it to a pro-shop and have the whole dash rewired.



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"Find a profession you love, and you'll never have to work another day in your life."
-Confucious