My friend has a 2023 Highway King, ie Road King, he wants to add a GPS to his bike. HD dealer says $250.00 for the part and installation, that's B/S in my book. I, then as I was looking I found wire under his head light.. told his I could run a fussed line off the battery. Anyone know what this is, has brown with a yellow line the other wire forgot what color it is.

 

You’ll want to have “switched power” so the plug in is not always hot. Before I took delivery I had the dealer install a Harley cigarette adapter style plug in on the handlebars so I can power phone and GPS. I believe it’s wired to an accessory plug under the right side cover on my 2024 police Road King (which ought to be in the same place as the 2023 Highway King)

I think the part was $110, and of course hourly rates being what they are, plus “shop supplies, tax and KY jelly” I can see a $250 total charge

 

A little difficult to understand what exactly is the need.
Do you require a 12+ power source or an actual GPS.
If you require a power source for a GPS then perhaps a tap into the accessory line would be an option and then you decide if you want a power outlet or something else.
Generally a tap under seat will provide choice of switched power or non-switched.
Some years of the road king model do have an unused 12+ power source for a fender tip light that could be used for a low draw 12+ power BUT keep in mind that many people forget "LOW draw".
Then they try to plug an inflator and get upset that a fuse popped.

 

Maybe that $250.00 dealer charge for parts & labor isn't so much B/S after all?