Amplifier shuts off when boat gets over 13v

CatriderF7

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This winter i installed a 1000w Lightning audio amp to power 6 Pyle 6 1/2 inch speakers. Its worked fine everytime Ive used it for hours at a time in the garage. But when I took the boat out this weekend for the first time it works fine at idle but when I start getting on the gas and the voltage comes up over 13 volts the amp shuts down. when i slow back to idle it comes back on. Ive re done this several times this weekend and it works the same everytime, right when the battery gauge hits 13v the amp shuts down, stereo stays on tho.

Is this just because its a cheap lightening audio amp? Ive installed several amps and stereos in cars and never had this happen, and most cars run more like 14-15v in my experience and ive never had one shut off because of too high voltage. My amp is ran straight off the main power going to the fuse panel. Anyone had a similar problem and know how I could fix this with a voltage regulator or something without replacing the amp? I have other Amps i could use but this amp is mounted under the steering wheel and all wires are cut to length to fit it so Id rather leave it if I can
 

matt167

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Re: Amplifier shuts off when boat gets over 13v

Check for A/C voltage. Most Amps have a failsafe where they shut down if too much A/C comes thru.
 

CatriderF7

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Re: Amplifier shuts off when boat gets over 13v

its a 1999 Bayliner 2050SS with a 5.7L 250hp I/O
 
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CatriderF7

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Re: Amplifier shuts off when boat gets over 13v

What do you mean A/C? I didnt think theres AC and DC coming thru the same wires is there?
 

matt167

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Re: Amplifier shuts off when boat gets over 13v

There is always a small amount of A/C current in a D/C 12v system with an alternator. Less than 1/2 volt A/C normally but if the diodes start to go bad, it can spike higher than the system voltage... You should be getting 13V at idle. If you only get 12V-12.9v at idle, that suggests a problem. If your running below battery voltage ( 12.6V ) than there is a big problem
 
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Re: Amplifier shuts off when boat gets over 13v

I agree with matt167. Somethings happen so fast that the meter on dc will not read it. Try putting a meter on the battery or wires set to ac and see if it reads anything
 
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Splat

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Re: Amplifier shuts off when boat gets over 13v

If you have a neighbor with a oscilloscope you could get a really good look at it. The ripples coming off the rectifier are quite obvious as the diodes leak and fail.
 

generator12

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Re: Amplifier shuts off when boat gets over 13v

There is always a small amount of A/C current in a D/C 12v system with an alternator. Less than 1/2 volt A/C normally but if the diodes start to go bad, it can spike higher than the system voltage... You should be getting 13V at idle. If you only get 12V-12.9v at idle, that suggests a problem. If your running below battery voltage ( 12.6V ) than there is a big problem

AC means the voltage reverses on each cycle.

I've never heard of this on a DC system, alternator or not. Do you mean AC or pulsating DC?
 

bruceb58

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Re: Amplifier shuts off when boat gets over 13v

Put your meter on AC and report what you read. Alternators generate AC which gets rectified to DC unless one or more of the rectifier diodes gets blown as Matt mentioned.
 

MH Hawker

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Re: Amplifier shuts off when boat gets over 13v

I had a rectifier do that on mine last year it was failing but hadn't went completely out but it was throwing a good amount of AC into the system.
 

TerryMSU

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Re: Amplifier shuts off when boat gets over 13v

The AC is superimposed on the DC. So what we are talking about is a varying (AC) voltage riding on the DC level. I believe this can be measured with most meters by switching the meter to AC. The problem is that this "AC" voltage may be directly conducted to your speakers, resulting in (at best) a lot of noise. Also the additive value of the DC, plust the peak of the AC may trigger some protective circuitry in your amp.

TerryMSU
 

CatriderF7

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Re: Amplifier shuts off when boat gets over 13v

I dont have any feedback coming thru the speakers when its running or any unusual noise. I put a voltmeter on it and at idle i have a little over 14v dc and when i switch to AC i get .0 or .1 on and off, neither reading seems to change much as I rev the engine
 

Don S

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Re: Amplifier shuts off when boat gets over 13v

Your amp is bad.

All std. 12v alternators put run around 14.4V to 14.8v when charging.. As much as you don't want to hear it, your amp is failing.
 

bruceb58

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Re: Amplifier shuts off when boat gets over 13v

Well, that means its not your alternator causing the issue. Likely bad amp protection circuit.

Edit: Don beat me to it.
 

gm280

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Re: Amplifier shuts off when boat gets over 13v

The actual technical name for A/C riding on a D/C voltage is called ripple voltage. And YES every alternator will produce such ripple voltage too. Once rectified it still has ripple voltage along with the D/C voltage. You amp's input power supply side should have some filtering to remove most of it, but even the absolute best filter systems still can't remove all ripple voltage. So a good O'scope could easily display that ripple...
 

CatriderF7

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Re: Amplifier shuts off when boat gets over 13v

Well I have a few more amps in the garage, I guess ill wire another one up and see if it still does it or not. Another thing I just realized is I think that amp was in the trunk of a car that I bought a while ago. This might be the reason it was left in there LOL damnit
 

Don S

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Re: Amplifier shuts off when boat gets over 13v

The actual technical name for A/C riding on a D/C voltage is called ripple voltage. And YES every alternator will produce such ripple voltage too. Once rectified it still has ripple voltage along with the D/C voltage. You amp's input power supply side should have some filtering to remove most of it, but even the absolute best filter systems still can't remove all ripple voltage. So a good O'scope could easily display that ripple...

Could you post a picture of an acceptable "ripple" as compared to an un-acceptable "ripple", and what type filter would you recommend in such a case. Also, ............ :sleeping:

Come on here guys, this isn't a spacecraft for crying out loud. It's a boat with an alternator with an amp that is failing. Stop blowing a lot of meaningless smoke up his exhaust pipe ...............
 

bruceb58

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Re: Amplifier shuts off when boat gets over 13v

So a good O'scope could easily display that ripple...
He doesn't need an Oscope. Measuring with a meter set to AC is sufficient. He has done that and the AC he measured sounds fine.
 

gm280

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Re: Amplifier shuts off when boat gets over 13v

Could you post a picture of an acceptable "ripple" as compared to an un-acceptable "ripple", and what type filter would you recommend in such a case. Also, ............ :sleeping:

Come on here guys, this isn't a spacecraft for crying out loud. It's a boat with an alternator with an amp that is failing. Stop blowing a lot of meaningless smoke up his exhaust pipe ...............

Don S, I expected better then this from you...SMH. Acceptable ripple is depended upon what the power supply will be powering... I can't believe YOU tried to belittle me on this... I seriously thought way better of you then that... I was merely suggesting that anybody (not just the OP) can/could see such ripple visually with a O'scope... Really...SMH! :eek:hwell:
 
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