If I was home I could do you a diagram. Here is what you do.
1. Buy a 10 Awg Red wire and Wire loom for it AND a Mini Blade 30 AMp Fuse and Fuse holder. (Because your bike takes mini amp anyways and has accommodations for a spare in the fuse box)
2. Attach the Fuse holder to the wire on one end, Solder the connection and heat shrink it and friction tape it one layer. 2a, Now slide the Wire loom all the way down the wire and tape it every 8 inches or so and to the Fuse holder wire. 2b Take the other end and run it under your tank and into the headlamp housing where all the other wires go. Secure the wire and be sure your routing does not contact hot points. I use the Velcro Wire securing strips and attach to stock wire harness.
Congrats, You now have fused Beefy power to your headlamp. ArG ARG!
3. Buy Your Waterproof Relay. (I have used a normal good quality relay with success by waterproofing it myself in some fashion, rescue tape, a baggie, a Golf club tube,)
Now you are ready to wire your relay. All you ever want to know about a relay.
But you merely need this one. A simple 4 pole relay. If you find a 5 only, Just forget the middle pole.
4. Connect a Male Spade to the wire from your battery (The red fused Loomed wire that you ran into the headlamp housing. Now, 4a. Now connect that wire to the #30 on the relay.
5. Connect a Grounded wire to the 85 Terminal. (I like a separate ground from the battery myself, but there are ground wires already there you can tap or use a grounding (Star Washer and ground to a metal frame ground)
NOTE, THe reason I run the seperate ground is to isolate the system from the factory system, that way if you get a ground problem on one circut you don't have it or are unlikely to have it on both circuts.
6. Hook the wire that supplies power to your Aux lights to the 87 Terminal.
7. Here is where it gets tricky. (Sorta) The 86 Terminal TRIPS the relay. If you run that direct to your high and low OR high OR low Headlamp power wire, the Aux lights will come one when that circuit is energized.
THE LAW is it must only come on with the Low Headlamps. So you would hook it to the Low beam POS wire.
If you want it to come on with both, You just hook it to any wire that comes on with the bike key Ing ON!
7.a I suggest, you hook it to (By a Tap) any wire that comes on with the Bike Ing on. Then Put a switch in that line. (You tap, then cut the wire and switch it, a very small switch such as the stock sized aux light switch is all that is needed since the RELAY and HEAVY wire is going to carry the load, that switch is just going to trip the relay.)
In this way.
Big power comes from the batter,
Goes to relay,
Relay gets tripped when bike IGN
. is on,
Power flows to lights. (When switch is on)
Yet, if you have bike trouble and want to cut the extra drain, you simply switch the switch off for extra cranking capacity.