What do these wires do? Neutral/Safety Switch

[JFetter]

Hello,

My reverse lights have not worked since I bought the truck. (78 K10, auto)
After tracing down the wiring, I found that my neutral safety switch is totally missing. New one on the way...

So I'm pretty sure the light green and dark green connector is for my reverse lights.

Then there are the yellow and purple/white, which have been connected together. This if for the start circuit?

Then that leaves this purple wire all by itself not being used. Does this belong on the neutral safety switch?

Thanks!

[rs72z]

The 2 purple wires are the starter circuit. The yellow wires has been added. Does it go to the starter?

[kustomrust82]

i believe mine were yellow and purple, 82 dually. my coloum was worn out so it was hard to line up the shift to start it so i looped the safety switch. just have to remember to not staart it in gear lol

[motornut]

79 auto

[hatzie]

First image is the Backup light plug.
Not sure where the yellow wire came from... Got an extra ignition switch plug?

1978 PPL/WHT is Circuit 5 the start position on the ignition switch. PPL Circuit 6 goes to the bulkhead plug and then the start lug on the starter solenoid.

1979 YEL is Circuit 5 the start position on the ignition switch. PPL Circuit 6 goes to the bulkhead plug and then the start lug on the starter solenoid.

You can find the GM schematics in my sig.

BTW according to the schematics it shouldn't start.

[rs72z]

I need to look at my 78 i dont ever remenber seeing a neautral switch with different color wires till now.

[rs72z]

Not sure when they changed them but my 78 has 2 green wires.

Just now saw the post above, there's my answer.

[motornut]

knew i'd seen yellow but couldn't find the 78 before,just took another pic
78 auto

[JFetter]

Hmmm, the plot thickens.

So 78 has both wires purple, in the start circuit.

It's almost like a 79 steering column is installed?

I'm going to have to trace some of these down and let you know what I find.

Thanks guys!

[JFetter]

Just an update: The purple wire that is not currently being used must have gone bad at some point an PO just left it there. He then ran a new yellow wire to the starter.

Just got my new Neutral switch, connected everything and success! We have reverse lights.

Thanks!

[HotRod C/10]

Bump for N2Trux

[N2TRUX]

Originally Posted by HotRod C/10

Bump for N2Trux

Thanks for the bump. I will be back under my dash soon.

[N2TRUX]

What I was able to determine after in depth investigation is the plug that I have loose doesn't go anywhere. It has a jumper built, so it goes no where.