When using different instruments than the stock instrument cluster it is handy to still be able to have a neutral light and start the bike in neutral.  In order to do this you need three normally open relays in series and a 12V diode. The diode keeps the neutral light from coming on every time you pull in the clutch.

I use waterproofed PCB relays do accomplish this.  Here's an example. I soldered up three relays, placed small pieces of Popsicle stick between them, wrapped them in electrical tape and then filled the tape with epoxy to hold them together and waterproof them.

To keep the diode leads from breaking I solder wires to them, place the diode in a short piece of straw and then fill it with epoxy.

© 2013 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.