Reverse lights and Neutral Safety Switch

[Jason Bourne]

I searched the site and found a lot of good information on the NSS. The reverse lights on my sons truck do not light up. I unplugged the reverse light connector from the NSS. I measured 12V on the dark green wire. I then jumpered the dark green and light green wires together and the backup lights came on so I know my issue is with the neutral safety switch.

It was getting dark so we decided we would look into it more on another day. We left the reverse light connector unplugged. When my son went to leave the truck wouldn’t start. Does the dark green wire provide power to the neutral safety side of the switch? I know the neutral safety switch circuit is the purple wires that get plugged into the NSS. My initial thought was these 2 circuits would be independent of each other.

My son plugged the green wire connector back in and the truck started. It’s possible that when doing that he bumped and moved the NSS or the purple wire connector, and that is why the truck started.

From searching through the other threads I know we need to try and loosen the screws on the NSS and slide the switch around to find the sweet spot. I’m nervous about messing around with a 50 year old brittle plastic switch. In case we end up breaking the switch can you jumper the purple wires together to bypass the neutral safety and start the truck? Do you have to supply power to the purple wires from the green wire?

Thanks for any help.