My 1966 Mustang with automatic transmission does not have backup lights. I would like to add them. So I am trying to determine how much wiring is required to do this.

After studying the wiring schematics, it appears that the starter neutral switch does two things:
1. It completes a circuit when the transmission is in neutral or park.
2. It completes a circuit when the transmission is in reverse.

In the engine compartment there is a set of wrapped wires coming up from the transmission that connect to two male/female plugs then go through the firewall above the (driver's) right main connector.

I have verified that the circuit of one of these indeed is completed when the transmission is in neutral or park. However, when I place the transmission in reverse, the other connector does not have a complete circuit.

My conclusion is that I cannot get backup lights to work with what I have.

Is this correct?

Thanks,

Bob O'Hara

 

looks like black-red is the wire your looking for from the NSS, and ground the bulb chassis. try this link. http://www.hammar.dyndns.org/~djhamm...6/66exter1.jpg

 

The switch makes continuity when in reverse thru the second set of contacts on the NSS. your can check the adjustment of your NSS by placing the trans in N and P and checking for starting in in only those two places. If so the adjustment is Ok and you have a bad NSS reverse switch. You can also put the trans in R and monitoring the switch's reverse circuit output, loosen the switch body a little and rotate it slightly CW and CCW and see if you get a circuit reading.

 

Thanks! as soon as I reinstall the wiring harness I will check this.