DS Headlight Switch

Well after all the phone calls and e-mails saying the the DS headlight switch I purhcased would be able to handle my new 100W headlight, the hi/low beam switch smoked and melted.

So I spoke with the company that sold me the switch, they contacted K&S who is the manufacturer. K&S e-mailed me stated the switch will work just fine with that much current (around 8amps). I then called Baja Designs, and they said their switch is used all the time with the same kind of 100W setup (though their assembly is wired a bit differently, but looks to use the exact same hi/low switch). I even called the guy at fourstrokesonly.com who sells a similar, if not the exact same unit. He said it should work just fine.

So whats up??? I know its not the wiring. I have 2 wires coming from the stator, then connected to a 200W AC regulator, and one wire from the regulator goes to the headlight switch main power, the other goes to the headlight ground, then the hi/low wires from the switch go to the headlight. And it all worked perfectly.

The wiring all held up just fine. No melted insulation or anything like that. It was the actual switch inside the DS assembly that completley melted. It got so hot that it melted the solder right off the low beam wire (after completely melting the switch) and the wire fell off causing the smoke to stop and the headlight to turn off. There was even a nice solder blob on my handlebar when I took the switch off.

At least the rest of the assembly works, and the switch is removable. So I'll just plug the hole, and run a seperate switch for hi/low beams that I know will handle the power.

Anyway, don't use a K&S DS switch assembly and run a 90/100W headlight through it!!!

If your pulling 8 amps through the headlamp switch. Use a 4 pin relay. pins will be numbered 85-supply B plus to it. Pin 86-ground. Pin 87-power and pin 30-load. Fuse pin 85 with a 10 amp fuse. U can use a small iso relay for weight and size. Use the relay to carry the amp load. If u need a samll iso i have some in my tool box at work I can send u a couple. This should be the ticket.

Ya, I might have to go with a relay setup. But I'll need two since I have a hi/low beam I want to switch. If I can find a replacement switch for my DS assembly (the little red push button) then I'll replace it and use 2 relays for the load. But if there is no replacement I'll find a heavy duty on/on switch and mount it to the bars and run the headlight directly through the switch.


I purchased two 12V 30A relays from Radio Shack today, and mounted them into my headlight assembly. Came out real clean. Everything is wired and ready to go except for my hi/low switch.

Does anyone know where I might be able to get a replacement hi/low switch for a K&S Dual Sport handlebar switch. I have the one pictured here . All I need is the switch with the red square button on it. It comes out of the assembly very easily and only has 4 wires soldered to it. (one being the blue hi beam LED).

I hate to have to buy another $60.00 assembly just for a $2.00 switch especially when this assembly has only been used for 100 miles.

If anyone knows where I might be able to locate a replacement switch please let me know.


Is your AC regulator before or after the switch? If it's after then that is the problem. Those regulators work by shorting out the AC. That will be more amps than the headlight. Maybe as much as 20 depending on how you wired the stator.

Its before the switch at the stator. The headlight switch is just not desgined to handle more than around 2A. It is very small with tiny contacts housed in very thin plastic with no type of heatsink. I am surprised that my 35W headlight didn't melt it first.

Not sure how they can sell this in a dual sport kit and not even mention the necessity to use relays. I just purchased the switch, but they have the same switch in their complete DS kits with complete wiring harness.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now