Amplifier Wiring

[Thomas Sayle]

I have decided to add two amps to my new boat. One for existing speakers and one to power a sub that I will add to console.

I found a set of wires under the console that are not connected, but have a white clip attached to them.

In an effort to try not to run power wires from the battery over, I’m wondering if those wires would be sufficient. They look to be a 10-12 gauge stranded wire.

Plan is to connect to a distribution block and then branch to amps from there. Of course fuses will be added to everything.

One amp is a 4 channel and supplies 100w per channel. Sub amp is 250w total. I am a little concerned about amp draw as most amps are not efficient. Anyone used these wires in the past for amps? I have been told that those wires are there for the sport arch but I wanted to ask first.

Running power wires from battery to console seems like a steep task with the amount of covers/shields/plates that would have to be removed.

Thanks in advance!

 

[cwag911]

I believe you're going to have to run heavier wire to the console for amps. It's pretty easy to do and I did it for a power steering add-on. Why are you not getting a sub with a built in amp?

 

[H2GO]

12 gauge wire will get you in the neighborhood of 10 amps reliably for a 15 foot run from battery to helm. If your amplifiers are rated at 350W rms total and you are using the rated speaker load you are looking at 29.6 amps peak at full output. If you have clipping it could climb even higher for short bursts. You also might run into significant loss due to the series resistance of the smaller wire which will cost you energy in the form of heat. If you want a clean and reliable system you might consider something larger size wiring. Looks like 8 gauge or larger would be a good choice. Fuse size at the junction splices should match the smallest gauge wire downwind of the splice as you know. Strongly advise a fuse close to the battery as well sized for the wire gauge you go with. The ground return to the battery should also be the same size or larger as well. See below:

 

[Havasu]

Actually running new heavier gauge cable from the battery area isn't too difficult. I ran some cables from batteries on the port side over to the starboard side and up to the helm. The 3' fish pieces from Harbor Freight really helped a lot. It is some work but I think you won't be happy trying to use smaller gauge wire. The last thing you want to do is starve an amp of power and push it. Easiest way to blow an amp. I'd just run new power and ground cables up to the helm and terminate them each to a distribution block. That way your amps will be happy and you'll have a power center should you want to add something else in the future. And the install will be nice and clean. Just my .02.

 

[gnc1017]

Also keep in mind that to prevent a fire, your source fuse (at the battery) must be sized according to the wire size, not the amp. That very, very likely will just result in you constantly blowing the fuse.

As stated, with wire fishing sticks and fish tape, running new larger cable isn't as bad as you might think as you don't have to take all the panels off.
Just remember you need both larger power and ground.

 

[Thomas Sayle]

Thanks for the feedback guys. I have my amps mounted and wired up, and will be attempting to run the power wires tomorrow. For those that have done this before, any tips or tricks you can share? I have the rods and a small fish tape. My goal is to not remove any panels as I am not real sure I could get them back on properly. Thanks in advance!!

 

[Havasu]

I didn't have to remove anything. Just take your time and do it in steps. It's really not too bad a job.