Hey guys, What does the accessary switch on my 08 Ultra dash control?
And where is the plug? under the seat? what does it look like?
I looked at the wiring diagram in my service manual but couldn't find a termination point, other than the cigarette lighter plug.

 

https://www.google.com/url?sa=i&sour...&rct=j&cad=rjt

 

I wouldn't recommend anyone doing this but I spliced into the wires for a handlebar-mounted USB power source controlled by that switch (Road King - no fairing). The wires still run under the seat so I can use them later if need be.

 

made it harder than is has to be- all USA models have an unused power source attached to the headlight loom ( it is for the Euro position light):
orange/wht...black is ground:



mike

 

Nice to know...I wondered what that was.

 

This is my specialty.

 

the switch controls a relay,the relay supplies power to the plug under the seat. dont think the wires to the switch are designed to handle much of a load couple amps at most.

 

I added the HD accessory cigarette lighter socket. I zip tied it under my right side cover and can run my GPS, phone charger or whatever else can plug in. The switch turns it on and off.

 

There is no plug on my 08 ultra in the middle of the tank under the seat area, but there is a grey plug like that one under left side panel near fuse panel. I wonder is that it. Although this one has power all the time whether acc switch is on or not. But this might be because I have the harness installed that turns on my spots whether in hi or low beam.

 

mkguitar has a nice solution.
I went with this plug-n-play for a USB power plug by 3BR Powersport on my King. I run it with the main harness under the tank to the bars.
https://www.3brpowersports.com/PDF/T...ures_Rev_1.pdf