Reverse lights??????

3-wire means a '69-up neutral safety switch, which comports with your '73 transmission. The '68-down cars had the reversing light switch on the shifter itself. The centre pin of the 3-pin '69-up NSS is for neutral safety. The outboard two pins are for the reversing lamps. +feed via fuse --> NSS --> rear of car.

I'm having issues with my lights on my car. Its a 69 valiant, original /6 car, changed it to a 360 with 727, and installed a hurst promatic. The harness from the 3 prong NSS goes to a plug, that goes to a short pair of wires that goes to the bulk head in the engine compartment. On the interior side of the bulk head, there are no wires going to the holes the wires went to in the engine compartment. I found the plug under the dash that has the violet and white wires, but don't know where to plug them in. I don't think they plugged into the old steering column? The white and violet wires are for the back up lamps, but I dont know how to get everything connected. The hurst instructions say you don't need to wire anything on a 69 and later mopar.