RPOHara

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

groho

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

jlg2002

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.

RPOHara

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