Help with wiring diagram

[Island Medic]

I am trying to decode my wiring for the engine compartment. Please have a look at the picture. The diagram shows this in the engine compartment. Now it looks like the neutral safety switch and the backup switch is part of the column. So what is this then?

I am also looking for some engine compartment pictures of STOCK wiring harness locations. I want to get mine to look as close to stock with some minor mods like HEI,alternator and headlight rely upgrades.

thanks

[Wrenchbender Ret]

The NS BU light switch is on top of the column between the dash & firewall.

[VetteVet]

I saw your thread last night but it was late and I was tired so I decided to wait until today to post, besides I needed a little time to think about it and I believe and I am guessing, The standard shift guys may be able to verify for sure but it seems to make sense to me.

What you are looking at could be the connector for the reverse light switch mounted on the standard shift transmissions or on some models on the steering column. I defer to Ray McElvoy for his knowledge in this area.

Thanks to Wrenchbender for his excellent response in the second post, The automatic transmission trucks used the neutral safety switch as the switch to activate the back up lights when the shifter is in reverse. As well as it's main purpose to switch the purple wire to the starter solenoid.

Look at the diagram below and in the center you will notice the NSS and the dark green and light green wires for the reverse light function. If you follow these two wires you will notice that the dark green wire goes to the firewall junction block and the fuse panel, and the light green wire goes from the NSS to the rear light connector ( left upper edge) and then down to the firewall block connector .

These two wires at the firewall block connector then emerge on the engine side of the firewall and go to the small connector you have pictured. Which then goes to the reverse light switch for the standard shift trucks. You may or may not have this in your harness. The factory wiring diagrams may include both circuits or they may not depending on which model they are drawn for.


Here is the automatic diagram and keep in mind that the dark green wire from the fuse panel is actually the power wire for the lights and it goes to the reverse light switch and to the firewall block connector.




If you have traced the light and dark green wires to the lower left you can see where they go into the firewall block and this is where they exit in the engine bay and run to the transmission connector shown on the center right edge.



Ignore any arrows in these diagrams as they are for other issues.

I look forward to other opinions on this.

[Island Medic]

Ok now that makes more sense. I think you are correct. When you have a manual transmission there is no steering column switches so it has to come from somewhere. Mine is auto so the switching for both reverse and neutral will be from the column. So my harness doesn't have these wires so I am good. Whew! thanks for the reply. It really helps. I have been modifying the wiring diagram to fit my application I will be posting it shortly for some comments.

again thanks.