The way mine is wired right now.
The outside speakers run off of the front speakers of the deck.
The inside run off the rear channel of the deck through the amp.
So the inside front and rear right run off the same channel, same for the left.
The sub is off of channel 3 & 4 of the amp.
No surround sound like said when ordered, the way it is wired it is only a 2 channel stereo.
Like above the way mine will be wired if I ever get the trailer out of service, been there for almost 2 months, I guess shipping from Heartland is not like normal shipping, takes more than a month to get parts.
Outside will still run off of the deck, but with a switch so I can turn them off.
All the inside speakers will be off of the amp, will have surround now.
The sub will be off another amp I will add.