Boat Install - Help

[DJ FADE 10+ year member]

hey everyone,

the install was just finished on my boat. i'm running an infinity 7541a, powering 2 tower speakers and a cdt audio sub. there are 4 more speakers being powered off the alpine headunit.

now to the problem: when you turn the headunit up to medium volumes, it shuts off for a second, then comes back on. if you don't turn it down, it shuts off again.

possible causes: 1. there was apparently no place to ground the amp, so they grounded it to the metal on the back of the headunit. 2. the amp is running off 10 gauge cable.

possible solutions: 1. re-ground, but i don't know where.. because there's no metal chassis. 2. hook up another battery and daisy chain them together (i'm going to do this anyway cause i have the extra battery and it won't be hard). 3. you fill in the blanks.

any help is greatly appreciated. thanks so much.

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[SSS 18734 5,000+ posts]

just run the ground directly back to the battery

 

[DJ FADE 10+ year member]

but isn't the ground supposed to be less than 2 feet long?

and also, would that be the reason for the headunit shutting off? because the amp stays on.. just not the headunit.

 

[SSS 18734 5,000+ posts]

no, grounding it directly to the battery would be fine. Its only recommended to keep the ground wire short in cars, just so it can get to the chassis faster, which usually has extremely low resistance because of its large size. But I doubt you would experience any problems if you grounded directly to the battery. But maybe step it up to 4 guage cable.

btw, got pics of the boat system? //content.invisioncic.com/y282845/emoticons/veryhappy.gif.fec4fed33b4a1279cf10bdd45a039dae.gif

 

[DJ FADE 10+ year member]

oh that makes sense. thanks a lot. and yeah, i have no idea why they used such a small gauge on an amp that size. i'll step it up for sure. and no pics yet! i'll try to upload a couple and post them on this thread. thanks again.

 

[n2audio 5,000+ posts]

I hope the "installer" was an amateur and you paid nothing for it (or very very little).

Grounding an amp of any size to the HU chassis is completely ridiculous, and an absolute fire hazard. Where do you think the HU grounds to in the end?? The battery.

Try tracing that wire to the battery - you'd be lucky if it's no smaller than 12 ga and not picking up the ground for a couple other components - dash lights, horn, lighter etc.

Be glad your amp has been shutting down instead of melting the insulation off the ground wire.

I wouldn't let someone so clueless so much as TURN ON my boat set up.

The basic concept of a complete circuit hasn't sunk in yet.

 

[DJ FADE 10+ year member]

wow i had no idea it was that serious. thank you. the installer was a younger cousin of mine who did it for like $25. it sucks that i have to go back through and make corrections, but i'm glad that i caught the problems (with your help) before any permanent damage.

thank you so much.

 

[n2audio 5,000+ posts]

I have an amp in my boat just about the same size as yours. I used the 8ga kit from Wal-mart along with some extra 8 ga I already had to run the ground.

Since my amp is in the passenger's footwell , but the battery is on the driver's side of the engine I just ran the ground down the passenger side of the boat and grounded to the engine block.

It works perfectly.