I have a pyle speaker/amplifier on my 09 Classic. I ran the connector to the brake light. So the speakers are on when there is power to the light.

 

I would run the power through a relay that is controlled by the running lights. This way, the amp is on its own cicuit and can't mess up your running light circuit. Which wire you choose to tap into for the relay control will be determined by where you plan to mount the amp. If it is toward the front of the bike it will probably be easier to tap into the running lights inside the headlight jug. If it is mounted at the back (under the seat maybe) then it would be easier to tap into the rear running light wiring that is part of the spaghetti in front of the battery.

PS - I sent you a PM.

 

I installed a switched fuse block I tapped in to the tail light running light. Here is a link showing a picture of it from electricalconnection.com
You can pick up this type of set up from different places many online. This is just one example made by electricalconnection.com. It comes with everything you need including the relay switch. I plan to add other items like a charger for my phone. It even has a wire to connect a battery tender. Good luck.