I am working on the backup lights and need a wiring diagram of the neutral safety switch and backup light wiring. There are 4 wires on the plug, one shows battery voltage and if I power a second one it cranks over which is for the neutral safety part of the switch. I don't know which one is for the backup lights or what the other wire is for. The lights don't work if I power up the other two wires. I will probably have to run a new wire to the rear lights, but it will have to be ran under the truck because the inside has been completely customized. The van is a Mystery Machine Replica from Scooby Doo.