The back-up light wiring should go from the NSS forward, then across the dash to the drivers side, and to the back from there. ALL of the wiring for the rear part of the car runs down that side, afaik. The harness passes thru the rear bulkhead in the ds rear corner.

Don't know if this will help, and I'm going from memory here, but....



|UPDATED|9/28/2012 10:11:02 AM (AZT)|/UPDATED|

oh geeze... if you labled that correctly i have been bypassing that switch by going from the starer to the backing lights... the 12V from ignition switch is the wiring plug that i can't find then... i assumed that whoever did whatever to this thing just took out the backing lights.

Huh? Now I'm confused, but that's easy to do...
If you do not have anything plugged into the connector I labeled as 12v from ign switch, then technically, there should be NO voltage at the NSS anywhere...the pink wires carry the voltage.
Something stinks in Denmark, and I'm smellin all the way over here....

Lemmie git my Service Manual out, and verify all of the connectors on the NSS, but I do know for sure that the purple/white wire is FROM the ing switch, and the solid purple goes to the starter solenoid.
I also know that the light green wire is for the reverse lights....
Time for some research....but it's bedtime now. I'll be back in da mernin....

Well Joel i'm definitely not on a time frame to get it fixed! lol i should have it out of the paint shop in the next week or so.  But i can tell you that before i put it in there that it DID start without anything plugged into what you labelled the 12V form ignition plug.  I know I pulled the NSS apart at one point and put it back together when this problem first came up and it worked for a while then it suddenly started up again without anything plugged in there, that is what had me thinking that it was the backing lights, i also havn't had backing or braking lights on this thing since i bought it! lol  what are the odds that someone did a really poor bypass somewhere in the system that i have yet to find that has burned out since i did crank on the ignition a little much while first bringing the engine back to life?

Well Jon...after much tracing of wiring diagrams, and getting cross-eyed, I have come to the conclusion that you may actually have the wrong NSS for the car. EVERYTHING I have shows the '75 with the seatbelt interlock system....all of the diagrams, and troubleshooting info show it. However, we know that the system was dropped during the '75 year model. The NSS you posted the pic of is for the seatbelt interlock system, which explains the extra plug you have no corresponding connection for.
My opinion now is, that you need to get a NSS for a '76. You should only have 4 wires on the switch. One power(12v) with key on, one for the reverse lights, and the two for the starter...that's it. If I look at diagrams for the '73, or the '76, that's what they have. Diagrams for the '74/5 show the switch with the lt green/black wire as part of the seatbelt interlock, going to the relay...that you do not have. This explains why it starts with you jumping across the connector with the  lt green/black wire.
As to how to explain how you were able to start it before, I can't.
There is probably a way to use the NSS you have, but you would need to use an ohm meter, and see what each pair of the wires do as you move the switch thru it's travel. You really only need to have a connection for the reverse lights, and starter. I think if you simply jump across the two purple wires in the vehicle harness, it will crank...but it will crank in any gear, so you need to be careful that it is in Park.

okay, so today i finally made it down to the car and put the switch i have now on the car and tried to jump between the extra wires that are on it so that it would complete the circut and would allow me to start the car in any gear.  When i jumped the plug here the car will crank even with the key in only the acessory position.  will a 76 plug really fix all this?

Yeeesh!This is really getting confusing now! You say that the plug with the two purple wires is HOT?? There should be NO voltage on either of those wires until the key is turned to "Start"....
That is weird...

Hmm, the "purple wire" deal. I remember that wire well. 

How hard would it be to check the NSS w/ a VOM?  That would either eliminate it as the problem or indict it.

Well i finaly have the car back from paint... guy stole my money and didn't paint it... Sarge, what troubles can you tell me of your purple wire issue.  I've been thinking about this and it seems like the purple wire is always hot if the key is turned.... any thoughts?