How To: '12 WR450 Taillight & Start/Kill Switch

yeah, I considered adding a relay too, but figured I'll just keep it simple and don't want to ever be stranded because the relay failed.



So I finally got some free time and came back to rewire the kill switch and brake light.

Brake Wiring Change:

- I found that you should not tap into the 12v+ wire coming from the 3-pin black connector that is for the electric starter. Originally I had tapped into this wire to bring 12v+ to the brake switch and when activated it would send 12v+ back to the taillight. This caused issues because with the low power OEM taillight I knew I heard a faint clicking sound in the motor. It was like I was getting feedback and the electric starter was trying to activate when I pressed the brakes. After I created my own custom taillight that was much higher power than OEM it was obvious I was correct. With no other changes other than putting my taillight circuit board in, the first time I pressed the brakes it was a full strength start from the starter. It was funny hearing the bike trying to start when using the brake lever.

I disconnected the stupid 3 watt running light in the headlight because it serves absolutely no purpose. I scavenged the power for that light since my taillight I made was ~4.25 watts and the stock one was 0.3 watts. So I only added 0.95 to the bike. The other reason I disconnected the running light was that the connector is up in the headlight housing and is a convenient source for a switched positive and negative signal. So anyways, I ran the 12v+ wire up to the brake switch for the supply signal and didn't need to change the wire I already ran back to the taillight. This solved the starter issue.

Kill Switch Wiring Change:

As you may have seen if you read this thread, if you use the OEM R6 switch on the WR the switch's operation is backward. The OEM R6 killswitch is meant to be in the closed position to let the R6 run. When you flip it off it breaks the connection and kills the R6 bike. You can use this on the WR without modification, but the operation will be reversed since the switch needs to be open to let the bike run. This can be reversed pretty easily and by using very small components instead of bulky relays. They are small enough that you can put them inside the wiring harness and no one would ever know the difference. The killswitch only uses 0.24mA so you do not need a component that can handle a lot of current. So let's cut to the chase and figure out how to get it done......

What you need:

- (1) 2N4401 NPN Transistor from RadioShack $1.49 Click"]http://www.radioshac...=2062615

- (1) 1K Ohm Resistor from DigiKey $0.29 Click"]http://www.digikey.c...D/594732

- (1) 100K Ohm Resistor from DigiKey $0.29 Click"]http://www.digikey.c...D/594692

If you are a schematic kind of person:


I personally prefer wiring diagrams over schematics so here is the above schematic translated:






Side note....You can also do this same thing with PNP transistor but the connections and components get moved around a little bit. So if you can't find an NPN transistor, then use this schematic instead:


Final product:

The transistor and two resistors are inside of the shrink tubing inbetween the red and brown wires. Once you pull the rubber OEM tubing back over the connections everything disappears and looks factory. The white connector is what I use to connect to the WR's factory harness where the running light bulb used to be. They are the OEM connectors that Yamaha uses and are water/dust tight....much better than butt connectors or spade connectors. You can get them from any local shop that sells K&L Supply parts (K&L has a downloadable catalog...go to page 119 of the downloaded catalog.)


Edited by DuncR6

I have a question about this, if the switch is closed when running, why cant you just break the 12V connection to the actual ignition switch?


in other words. leave the OE ignition switch in the on position, then take the 12 volts that goes into the switch, tap into that. run it through the R6 handle bar switch, then back to the ignition switch where the power was going originally?

as far as killing the engine, I am pretty sure if you cut power to the ignition switch it's the same thing as turning the switch off, and that will certainly kill the engine as well as any lighting.

turning the switch back on will reconnect power..


I have a 2013 and I am also looking for a way to kill the power and stop the bike without having to hunt for the ignition switch. I keep leaving it and the headlight turned on.

I want to remove the red kill button so it cant be used to stop the bike. use the handle bar switch from the R6 to start and stop the bike. this will prevent the headlight from being left on.

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