System check in new boat

[chpthril]

The PPi has its own internal internal (chassis mounted on the side) fusing, so it does not need additional circuit protection. if your trunk line is properly protected, you will not need any additional circuit protection for the addition of the amp.

[Bigdog0598]

When you say my trunk line is properly protected what do you mean. What should I look for? I know have have a bank that each amp goes to but after or before that?

[chpthril]

Trunk line would the main cable from the switch to where the amps are mounted. it would branch off through a fused or non-fused distribution block to each amp. When installing multiple amps, this is the preferred setup, as opposed to running a dedicated cable for each amp all the way back to the switch. Without knowing exactly hoe your dealer did the install, my comments are only based on all other things being correct. You noted an open in the distribution block, so that would lead me to conclude that this is the way your cabling is configured. So, if that main cabling is large enough to support that 4th amp and the main circuit protection is enough to handle the additional load, you should be good to wire in that new amp using that open output on the distribution blocks.