Emerge Amplifier Wiring

[tspnmb]

Picked up a 2010 Emerge for a really good price and trying to add an amp and a set of speakers.
Did this on our old ezgo but the Tomberlin is a little different.

I am not putting in a head unit. Just a marine amp that has built in bluetooth so I will just connect with a phone.
Trying to find where to connect it up. Simple red / black / blue wires out of the amp. I want it only be powered when the ignition is on.
It has the 48v reducer for the lights , wiper etc. Out of the 48v reducer the black yellow and green go to the "DC changeover contactor and diode assembly" (according to the manual)
and the red goes back into a cluster of wires.

If anyone has experience with hooking up a stereo or amp and can guide me where to tie into with the amp I would greatly appreciate it!!

thanks
I can post pictures if it helps..