Hooking up an amp, what am I doing wrong?

[bowrider200]

Trying to hook up an amp and 2 10" subs in my boat. The amp is a Rockford Fosgate 201s and I am (hopefully) going to push 2 planet audio dvc 10s. For some reason when I turn the radio on the amp will not turn on. It turned on the first try and started cutting out and then quit coming on. I checked the voltage at the amp terminals and I am getting around 12.5 volts at the amp until the radio comes on and then the voltage drops to around 6 to 7 volts. I hooked the amp up in my truck and it works fine, then back to the boat and nothing. Is there something different about wiring for boats vs automobiles? I only have a 1 battery set up right now, do I need another one?

 

[Midnight Krawler]

Re: Hooking up an amp, what am I doing wrong?

Sounds like a bad connection or the wire is to small to handle the current. A car amp uses a lot of amperage. 12 gauge wire should be the minimum for both the positive and negative.

 

[Silvertip]

Re: Hooking up an amp, what am I doing wrong?

Or you have a battery that can't deliver the amperage the system requires. That may be because it is an older battery and is headed for battery heaven, or it is simply not fully charged.

 

[bowrider200]

Re: Hooking up an amp, what am I doing wrong?

Thanks, if I was to guess it would probably be my grounding point. The amp requires at least a 10 gauge wire, and the kit I used is 8 gauge. I may try to move the ground tomorrow to see if that helps, I used an existing grounding point where something else was grounded. I was just puzzled as to why it would come on once and quit. I even tried jumping from the power wire to the remote terminal and I did get the logo on the amp to light somewhat, but it was very dim.

 

[bowrider200]

Re: Hooking up an amp, what am I doing wrong?

I bought the boat in May of this year and am not exactly sure how old the battery is, I tried to look to see if they marked the dates on the sticker but couldn't tell anything. Guess if moving the ground doesn't work then that will be the next path I take.

 

[TSL812]

Re: Hooking up an amp, what am I doing wrong?

Where is it grounded and what size wire, 8 ga also? Ground wire should not be smaller than the the power cable. If that's all good I'd check the battery.

 

[reddogg]

Re: Hooking up an amp, what am I doing wrong?

I'd recomend that you convert to a dual battery set up. Amps will draw allot of power and will draw more the louder you go with it. If this is on an outboard, you don't have the option of instaling a high output alternator to take up the slack of keeping the batt charged and powering an amp pushing 2 10's. Get a perko dual batt rotary switch and a second batt, that way you'll have a dedicated batt for starting the engine and one for everything else. You don't want to be stranded because you ran your batt down.

Red

 

[bouttime007]

Re: Hooking up an amp, what am I doing wrong?

Yeah, definately go with 2 batteries.

 

[ac0j]

Re: Hooking up an amp, what am I doing wrong?

The only place you should ground an amp in a boat is at the negative post of the battery. What might have happened if your ground was "iffy" is that the amp tried to find a better ground through the RCA cables. This ALMOST always instantly damages the radio rca pre outs. Since you say it turned on the first time, and then started cutting out and quit. My money is on burnt up rca output grounds in the radio. When grounded right, the amp will still be OK, but you probably need to take the radio to the repair shop if you dont get sound from the amp when you get it to turn on in the boat.

 

[bowrider200]

Re: Hooking up an amp, what am I doing wrong?

Thanks for the info guys. I have a 4.3 mercruiser, and I do have a dual battery rotary switch but only 1 battery currently. The ground wire in the kit is the same size as the power wire. If I did burn up the RCAs hopefully I can change the ground and use the speaker level inputs for now. I will keep yall posted with any more info (problems).

 

[Silvertip]

Re: Hooking up an amp, what am I doing wrong?

Most modern electronics have "over-voltage" as well as "under-voltage" cutoffs which will shut down the unit if voltage goes over or drops below a certain threshold. Check the spec sheet for your unit. Those numbers are normally listed and are in the 10.5 - 16 volt range. Therefore, your unit measures 6 - 7 volts (your measurement) so the low voltage system shut down the unit.

 

[TSL812]

Re: Hooking up an amp, what am I doing wrong?

Make sure you have the same size ground all the way to the battery, not just to the "existing grounding point". I prefer to run dedicated power and ground cables from amp to battery. Hope this helps.

 

[bowrider200]

Re: Hooking up an amp, what am I doing wrong?

So it was my "existing grounding point" after all. Guess I'm just used to car audio where you can ground just about anywhere. I found the grounding terminal block under the dash where all of the electronics are grounded. It does have a run straight back to the battery. Luckily I didn't fry my rca outputs by my ignorance. I hooked it up and the 10s started hitting. You guys think I'll be okay with my ground, it looks to be about a 10 or 8 gauge wire straight to the battery, or do I need to run a dedicated ground just for the amp? Thanks again for all of the help.

 

[Silvertip]

Re: Hooking up an amp, what am I doing wrong?

Don't know unless you tell us what the maximum current draw is. Remember, that run back to the battery from the grounding point must also carry the current load from all the other accessories as well so it's not just the amp you need to be concerned about.

 

[TSL812]

Re: Hooking up an amp, what am I doing wrong?

Personally I would go ahead and run a ground for the amp.

 

[bowrider200]

Re: Hooking up an amp, what am I doing wrong?

Probably a good idea, think I'm going to go ahead and look at getting another battery also. Thanks again

 

[rhaser]

Re: Hooking up an amp, what am I doing wrong?

I have a 500 watt amp and 2 12's. the amp would cut out if i went past 1/2 volume. i ran 2 seprate wires to the batt. solved the prob. the boats wiring could not carry the amp draw. i also only had a starting batt and killed it playing the radio. i was able to pull start my out board to get home. now i have a large deep cycle/starting marine batt and switch. havn't had any probs but still have the starter batt hooked up but isolated just in case. hope that helps

 

[remarkable53]

Re: Hooking up an amp, what am I doing wrong?

We are a car/marine audio shop in Tempe, AZ and need 1st to ask you some questions about what your trying to do and why it's doing what it's doing, ok?? Ok, let me see if I have this right, you are wanting to install a Fosgate amp is it a mono (1 channel) or 2 channel? I'm thinking it's a mono but even though i sell Fosgate am not familiar with that model number. Now if it is a mono amp AND it will accept 4AWG power, ground wire USE IT. Also buy COPPER not the aluminum clad bs. You get what you pay for and there is a bunch of junk being sold. You will need two runs too. 4AWG positive and 4AWG negitive from the amp to the battery with a fuse or circuit breaker no more than 9" from battery. The closer the amp is to said battery the better for all parties involved. Now #2 the woofers.. 2 DVC woofers huh? Well are they 2ohm DVC or 4ohm DVC? How do you have these woofers wired, series or parrellel? This is critical because for instance if the woofer is a 4ohm DVC it can be wired to be 2ohm(parrellel) or 8ohm(series) and if you wire two 2ohm woofers parrellel will result in a 1ohm load at the amp and those 2 woofers will be your new anchors in about 3 hours of hard playing along with cooking the amp. I can easily walk you thru setting your system up for maximum punch and a trouble-free life if you want to email me with the particulars. I will also need some more info too... But what your describing is you cooking your toys... Tell me did you smell something like burning plastic or rubber? Did the amps light go from green to amber to red?? Hopefully you didn't fry all your gear.. Anyway if you have not solved your issue hit me up..

 

[bowrider200]

Re: Hooking up an amp, what am I doing wrong?

Thanks for the help, but I think my problem was my original grounding point. I found a 10awg wire going back to the battery and grounded the amp to that wire and it has worked fine since then. I don't know all of the specs on the amp because it was given to me by a friend (in exchange for first invite on my boat) and I believe it is discontinued. I found some specs online and the amp should be 2 ohm stable in stereo and 4 ohm bridged. The 10s are dual 4 ohm voice coils so I wired each one in parallel in stereo. The speakers are rated for 150w/rms and at 2 ohms the amp is rated at 100x2. I do plan on getting another ground wire specifically for the amp in the near future, and ultimately another battery. Due to all of the rain we have been getting down here I haven't had a chance to try them out for extended periods of time. They do sound good in the driveway though.