Hi
had my ignition switch go bad on me too, i replaced it with a generic one that fits on Japanese quad bikes ect. it has on key can't be withdrawn and off key can be withdrawn positions- simple right 4 wires coming out of it, Red, black, green and black with white trace.
after much head scratching, wire diagram's and google, came up with this:
Green wire and black/white wires on switch- can't be used, cut back and insulate accordingly
attached red to red (battery positive)
on the bikes side:
add a diode onto the grey wire
add a diode onto the grey/blue wire
attach black to green and join the other ends of the diodes together and join them to the black wire of the switch so solid black wire from switch joins to green wire of bike and the two diodes.
stripe of diode to be on the wire side where joining diode to the bike's wires
solder the two diode other ends to the black wire with the green wire to the black wire.
insulate the diodes carefully from each other before taping the whole lot up
I did this and I have reliable switch, have the rear taillight and park light working when bike on, but for obvious reasons lost the ability to leave the park light circuit on with key withdrawn as per the OE switch- but I'm not bothered by that.
Reason for having to use diodes is to stop the back feed of power to the rear taillight and instrument cluster when switching off remaining on.
I used 10A10 MIC diodes, a little heavy duty for the job, but it works, try perhaps try an 8 amp one not as much current drop going to the park light circuit, but its miniscule and is like splitting hairs. I used these as i had a few of them left over when i did my alternator charge light back feed mod.
