I wired a headlight and a tail light/brakelight to my 09 TXC450. I was relatively easy and took about 6 hours although I was doing it from scratch trying to figure out the best way to do it as I went as I couldn't find any writeups anywhere so I reckon now it would only take about 2 hours.
Things you need:
Headlight: I used Racetech V-Line headlight
Brake/tail light: I used a MCS universal enduro LED brake tail light
Brake pressure switches: Ebay M10x1.00mm 90 degree banjo bolt pressure switch x 2
Looms: Described below
Plugs: 1x 3 pin male plug to suit female wiring plug under fuel tank, a few waterproof male and female bullet connectors or similar
Wire: About half a metre auto wire or you can salvage some from the looms when you shorten them up.
For the wiring for ease of wiring and cost I used 2x cheap ebay looms. As i wanted the headlight and tail light to come on together and run whenever the bike is running and turn off when the bike turned off I decided to run both of them off the same relay so I used a cheap loom designed for 2x HID spotlight in car. Example:
Here. As the brake light only needed 1 output I used a similar loom for an LED lightbar.
Install the pressure switches in place of the existing banjo bolts on the brake master cylinders and bleed them up.
Take off your fuel tank and side plastics and locate the female 3 pin white plug (mine was discoloured a bit and covered in electrical tape). You can see it in this photo. The new male white 3 pin plug you can see in that photo I will get to later.
The plug has 3 outputs. 1 is earth, 1 is AC power straight from the stator which is only live when the bike is running, 1 is constant 12V DC (although mine wouldn't output enough amps to run the headlight and taillight effectively hence why we will wire them to the battery later.) Find which plugs are which using a multimeter. We only need to know the earth and AC one. The switches in relays don't care whether they get AC or DC power so we will use that to switch the circuits when the bike is on.
When you initially wire it all up don't shorten any wires and temporarily twist tie connections to make sure it was all working. Then you can figure out how you are going to route the wires, then shorten them to length, wire in plugs, cover with flexible conduit then zip tie securely to bike.
With the 2 ebay looms, take off the switches as we will not need them and cut off the switching wire (usually white) from the switch plug (NOT THE RELAY!!) as we will use that wire as our switching wire from the plug under the tank.
First we will wire up the headlight and tail light. Using the HID loom with the 2 outputs wire 1 output to the headlight wires and 1 output to the tail light wires. Wire the switching wire from the relay to the AC output from the plug under the tank and the negative from the relay to the negative on the plug under the tank. The positive wire on the fuse will go to the battery but we will do this later.
Next we will wire up the brake light through the pressure switches. This is a little trickier as we have to wire the switches in parallel but its actually pretty easy. It doesn't matter which of the 2 wires you use on the switches themselves. This is where you need to use some spare wire you have around. You need to run a wire from the AC output on the plug under the tank to 1 wire on the front brake pressure switch then from that wire to 1 wire on the rear brake pressure switch. Now wire the switching wire from the relay to the other wire on the front brake pressure switch and then from that wire to the other wire on the rear brake pressure switch. Now the brake switches will work independently from each other and both switch the rear brake light. Wire the negative from the relay to the negative on the plug under the tank. Now wire the positive and negative output from the relay to the brake light wire (you may not need to wire up the negative if like mine the negative wire for the brake/taillight was universal). Wire the ground from the relay to the ground of the plug under the tank.
Now you are all wired up. Now connect the positive from the 2 fuses to the positive of the battery. Start bike and the headlight and taillight should come on together. Pull the front brake and the brake light should come on. Push the rear brake and the brake light should again come on. When you turn the bike off it should all turn off. If some or none of this doesn't work go back over your wiring to make sure everything is in the right place.
Here is a wiring diagram I drew up
The loom you end up with with look something like this (although mine in this pic has an extra relay I was going to use for an LED spotlight for night enduros. The red bullet plugs go to the pressure switches.This pic has a couple of extra bullet plugs as I was trying to find the best way to wire it all up at the time. I have since tidied it all up.
Now just find a nice way to route it from the left side, up to the front and then down the right side to the rear brake switch, shorten up the wires, wire in some waterproof plugs, encase in conduit, zip tie in and ride away.
Another pic and a vid I had
Wire and plug going to the tail light
Video of it all working
https://goo.gl/photos/q264YWptAnMJumzY9
Hope this helps
