I was hoping to find someone who has wired the back up light switch in on a sm465 tranny. Im guessing its a ground loop switch, but I could be wrong. Also did you use any relays? Thanks very much!

most of 'em are, and no, don't use a relay. All it is, like you said, is a switch that provides a ground for your lights.

The backup light switch on my 465 has two wires (normal SPST switch, closed when tranny is in reverse). It is from a '72 Blazer.

It is like the switch on the wall of your house, it completes a circuit, the lights ground at the bulb socket.

thanks for the help. I just grounded one side and then hooked the other end up as the ground on the lights. worked great.