I am refurbishing a 2004 RoadKing and as I was changing the lights to LED with halos I came across an empty wiring harness in the headlight cavity. Any ideas what that is for?

I also have a left side switch which I can’t figure out or trace. The same one on the right operates the two front aux lights.!Any ideas what that one on the left could be for or if an auxiliary what is a good use?
thanks

 

The left switch is a aux switch, use as you please, I*'m sure the connector in the headlight bucket if for a extra add on of some sort, I'm sure so will be along shortly to give a better explanation.

rk classic.

 

The headlight bucket wiring harness on road king has wires that can be used to address other electronics on fairing bikes.
Second switch is auxiliary.
The connection for auxiliary was under seat on many model years.

 

I would hook up some type of light meter to it and turn on your ignition., if it lights up it will be a switched power source. My 2011 has 2 extra wires that I use for charging...

 

Pretty sure the red wire on the right of your pic is for a fender tip light. If you don't have a fender tip light, it's a switched 12 volt source. I used it to power my GPS.

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That plug appears to be the one for the right hand handlebar cruise control switch. Which you may not have, depending on which model RK this is.

 

That is interesting. Is that a doable addition or not worth the effort even if possible? I don't have cruise control on the bar at present and frankly bought this on a whim and thought they all had it - until getting home...

 

It’s probably possible, if you find all the bits and bobs. Is that worthwhile? That’s your call.

A throttle lock is about $20-40 though.