So i have now replaced the ignition switch, the starter twice, entire engine ignition system, and key tumbler.  I just got my new Neutral Safety Switch in, hooked it up and the car won't start... i can bypass the switch with a paperclip and the engine will fire right up, did i just get a bad NSS right out of the box or is there a bigger problem that i am missing?  The car has been doing this not starting from the key thing for a while now and i just don't know what else to do...

Do you really need a neutral safety switch?

Have you moved the shifter around at all while turning the key. The NSS will have some adjustment on it and you may have to loosen the screws that hold it down and move the switch a little. This is so it only will start in Neutral or Park. Yes you could have gotten a bad switch as well. The new one I put in mine only works in Park. The new headlight switch I got didnt function at all for vacuum. Yes Its very possible a new aftermarket switch could be bad! Arent these cars a blast! Best of Luck,
Rodney

To Gary, yea i think i do need a NSS because i will eventually lose the paperclip i use to start the car and would be stranded! lol

Are you SURE you do not have this relay on your firewall?



The wiring diagram for the '75 shows it to be there, and most all '75s did have it. The purple "Start" wire from the starter goes thru this relay, turns into a Lt. Green w/black tracer wire, then to the firewall pass-thru, turns back into purple, and then goes to the NSS, turns into a purple w/white tracer going to the ignition switch.
If you have 12v on the purple/white wire with the key in the "Start" position, and it still will not crank, the problem has to be down wind of the NSS. If, however, you are jumping across the purple & purple/white wires to crank it, the problem is BEFORE the NSS, or the NSS itself..
If you have 12v at the purple/white wire with the key turned to "Start", but not on the solid purple wire, the NSS is bad. All of these checks would be with the NSS plugged in.

So i went looking for that relay, this is the only thing it could be that i found under the hood.

Naw...that's the high speed blower relay.The problem with the wiring diagrams for the '75 is that they were originally drawn to include the seatbelt interlock system, since it was a government mandated safety item for ALL vehicles sold in the US in '74, and was intended to be continued. However....it was dropped sometime during '75 production. The early '75 cars had it, later '75s did not, but the wiring diagrams were not updated.
Even so, if you just take the relay out of the diagram, it would presumably just remove the lt green/blk wire out of the diagram/circuit, and that same wire would be purple all the way from the NSS to the starter solenoid.

so assuming my NSS switch is good would the problem just be located somewhere along that purple wire?  and this whole problem is made EVEN more fun with my partial color blindness, and purple happens to be one of the colors i have trouble with! lol

Well...also assuming you're getting a 12v signal from the ignition switch to the NSS. You say tho, if you jumper across the terminals AT the NSS, it will crank/start, right? If this is true, then the wiring from the NSS to the starter has to be good....and that also confirms that the signal from the ign switch is getting to the NSS, so....that pretty much leaves only the NSS as the problem.
I say this all the time, but "new" don't mean crap. I get new stuff all the time that ain't no good. How many new light bulbs have you ever put in that blew as soon as you hit the switch?

At this point, if I have read correctly what you have done, and that you can start the car by jumpering across the NSS, then I have to believe the NSS is the problem.


Another thought...do your reverse/back-up lights work? Do they come on when you put it in Reverse?

|UPDATED|9/27/2012 7:45:04 PM (AZT)|/UPDATED|

funny you should mention those backing lights... i have been looking for those wires that connect to the third part of the NSS for about 2 weeks now, granted it's been being preped for paint but i do visit often to do little odd jobs i have not been able to find whether that wire should come from the front dash or if it snakes in from the rear and behind the driver seat.  and i can't even find where the wires may have existed and possibly got cut at.  it is the driving force that has me considering replacing both my wiring harnesses.