2016 street bob. Trying to install the boss mcbk470 speakers. Research I’ve done says you don’t need the relay, you need to splice into the ignition wire near the fuse box. Has anyone done differently or know a better approach so the amp turns off when the bike does? The only wiring diagram I can find I will try to attach. I’m assuming the white/blue wire is the correct power wire.
thanks!

 

Personally I wouldn’t splice into anything. I would get one of those pigtails for an auxiliary power source and run your amp to it. You should have an open connector in the harness under your seat. Plug and play, no splicing existing wiring.

 

I did find that connector under my left cover. My instructions show I need to install a relay and run the wires. I’m assuming with this plug I do not need to do that? I’m thinking if I just run ground and power to the pigtail ground and switched power with the inline 10A fuse, I should be ok.

 

https://mstore.harley-davidson.com/s...B&gclsrc=aw.ds

The auxiliary power under your seat is tied to acc/ign. You won’t need a switch. Just plug in the pigtail and use the supplied open leads to land your amp wires and inline fuse.

 

10A isn't a whole lot but it wouldn't hurt to verify the Aux circuit capacity.

Is the amp and head really only pulling 10A, tho? That's only 120-140 watts total. Even the most efficient modern class D amps are only about 90% depending on load.

Edit: just looked up that Boss system. The amp looks suspiciously like a MTX MUD50.2, which is 100W RMS @ 2 ohm (50x2). I have one for some headrest speakers in my little car. 10A seems reasonable for that.

1000W, HA! Good ol' Boss marketing.