I came across quite a few fellas who were unsure how to wire new accessories on their bike. Those who are totally unfamiliar with electricity will be interested to know that if you add too much ballast (wattage-drawing devices) to your AUX plug in the headlight bucket, you are likely to draw more than 10 Amps, for which it is fused. The fuse rating is matched to the 18 AWG wire used by Suzuki, so the fuse protects the WIRE first (from overheating) and your devices second. Since we can't change the OEM wire from Suzuki running through the harnesses, we have to live with what they gave us: A 10 Amp circuit translating to a maximum of 120 Watts ballast.
Even if the fuse withholds higher Amps (and it usually will, which is quite contradictory to their purpose), your wires, now getting pretty warm in the IGNITION SWITCH, will slowly but surely damage the switch which may eventually fail. So you want to put add'l accessories on their own circuit with a relay.
A relay is an electric switch which, when energized, will close a second, totally independent circuit. Below is a drawing I made for a simple setup of wiring two add'l driving lights. Note that the rocker switch gets its energy from the IGNITION circuit and when turned on, will close an independent circuit (in the relay between poles 87 and 30) and safely run your lights (or anything you connect) on it's own, fused(!) circuit.
Why do we want a relay and not simply wire the lights directly to the battery? Well, of course you can do that, but if you do, the lights will come on whenever someone throws the switch, even if no key is in the ignition. Or, you walk away from the bike accidentally leaving your lights on. 3 hours before your battery is dead! A correctly wired relay will only allow the circuit to your aux. lights come on when the ignition is on.
Just for clarification on the drawing: This drawing assumes that you have a LIT switch where a little light comes on when it's in the "on" position. That is the only reason there is a third post on the green rocker switch - to energize the lit button. If you have just a simple, unlit toggle switch, it will only have two terminals, so you can forget the third one with the black ground wire coming from it (in my drawing I spliced it to negative in the circuit).
Also you will wonder why I just said that the AUX can handle 120 Watts but my lights in the drawing only add up to 110 Watts. You are correct, just that 120 Watts is the MAXIMUM load the wires can safely handle, but not continuously. So we're getting pretty darn close to their acceptable Ampacity, making it safer to go this route.
The wires coming TO the Aux plug in the headlight are orange with blue stripes (positive) and black with white stripes (negative).
There are wiring harnesses on the market that have this cicuit so you don't have to wire yourself if that's not your cup of tea, but they still usually need a little modification here and there. Check at autozone.com, Part# PL-HARN3
I used a 20 Amp fuse in my drawing, which is actually overkill for the driving lights. 15 Amps would do fine, even 10 in a pinch. Just make sure to match the fuse to the WIRE SIZE that it protects (see charts posted belows).
Hope this helps. Any questions, just PM me.