Back-up Switch Cables Missing

[RLM]

Hello,

Recently I was able to have the motor running in my 1978 911SC after a long 2+ years on and off top end engine rebuild. While checking all exteriors lights in preparation for the state inspection I noticed that the back-up/reverse lights were not working. I found out that the cables going to the back-up switch are missing. There are no loose cables under the car or in the engine compartment. I bought this car as a project and immediately started working on engine rebuild, so I am guessing someone in the past remove/ripped the cables. Can someone explain to me to where in the harness or else do I need to connect the cables that are supposed to come out of the switch?

I found some good information in previous thread about troubleshooting back-up switch and some diagrams, but honestly I am very bad at electrical diagrams. To where do I need to connect/jump the two cables I will be connecting to the switch? Can I connect them to the cables going to pins #5 & #6 just before they get into the 14 pin connector?

Any help will be greatly appreciated, and sorry for any dumb questions in here!

Thanks,
Rodney

[timmy2]

I have seen a lot of engine harnesses sent to me where people have cut off the wires going to the reverse switch.
The wires to the switch should come out of the harness just after the rubber block grommet at the rear sheet metal. They run through the entire engine harness from the 14 pin connector to the transmission area.
You could run 2 wires from the 14 pin connector along side the existing harness directly to the reverse switch if you had to.
I would solder them directly to the pins in the connector. The wire length is around 6 feet. Start with 7 feet and cut as needed. You will need to push them through the rear engine tin grommet or they could get cut. You should also sheath them in vinyl tubing for protection. There is also a hard plastic tube about 8" long that is used to secure them to the transmission housing.
Green/yellow and grey/(red?) are the correct colors for the wires 16 gauge.
I would try looking around on top of the transmission for the cut wires.
You will also need the correct connectors for the switch, $6 each, part number 911 612 907 00...
The rubber boot for the switch is NLA but I make them for my harnesses.

Hope that helps.
Dennis