Truck is a 71 and has a c6. Does anyone know exactly how the wiring from the gear indicator is tied into the starter circuit?

Ive ohmed out the switch. there are two red wires and two black wires. Both sets of wires have color stripes but i dont recall the colors at the moment. Both black wires go to one set of contacts, both reds to another. Each set of wires has two positions that close the circuit(park and N), but these are in different places. I was going to draw a picture but i didnt get the chance.

So what im doing is removing the gear indicator switch and im going to wire in a switch(hidden). Ive tried tracing everything and im able to start the truck with a jumper to both sets of contacts and their respective pair(black-black, and red-red), but i cant find this thing on a wiring diagram. So what im trying to figure out whats going on with two sets of contacts. It seems like red-red tie into the starter circuit but im not sure what the other set for? I just want to be sure there is no hidden function for the other contacts running to something that needs to know when its in R or something like that.

Thanks in advance.

 

Hi,

I think what you are looking at is the NSS (Neutral Safety Switch) which should close contacts in the Park and Neutral positions, and the other one would probably be the Reverse lights switch which come on- in Reverse. I could be wrong, I have a stick.

 

yup that is what im talking about but the second set of contact which would be R and 2 didnt make sense. i believe the R switch is on the tranny but thats what im looking to find out.

thanks for the reply

 

The NSS is at the bottom of the steering column thru 1977.

There is no separate backup (Reverse) light switch with an A/T, because the backup lights work thru the NSS.

C7TZ7A247A .. NSS (Motorcraft SW600) / Fits: 1967/77 F100/350.

 

So ND can you tell me why there are two positions for each set of wires? One set would make sense for Park and Neutral, but if the other wires are for Reverse it wouldnt make sense for the extra area where it completes the circuit.

despite my horrible drawing there is no overlap and the gaps between the red and black are a bit more. The black dot in the center doesnt represent any part of the contact circuit. This is the stud that the shifter arm where it comes out of the column contacts this assembly.




Do you happen to know which wires are for the starting circuit and which are for the Reverse light? I want to install a switch and remove the start function from the NSS. Its always caused problems for my cousin and i think using a momentary button(hidden) along with the key to start the truck will be nice.

thanks!

 

I have no clue inre to wiring. I'm a partsman, not an electrician.

I can look up anything electrical, but that's about it.

 

well i did a little work on it tonight and the black wires go to the reverse lights. the second contact is past the lowest gear so it doesnt come into play. The two red wires are for the starter circuit.

I pulled the unit apart(bending the sheet metal ears) and cleaned everything real well with electric parts cleaner and 1000grit sand paper on the contacts. there are two ball bearings that are spring loaded and pressed into a plastic groove. Im going to leave it in place but install a switch in parallel with it just in case it gives use trouble again. Id like my cousin not to have issues starting the truck.

Thanks for all the help guys.