Adding a backup light to Railking SD90

I can't believe it's that difficult, the only issue I can imagine is if the rear light outputs on the PS/2 board aren't active for the sound file.  Other than that, it's just a wiring exercise.

Front and back light operate as a pair so if you have front then you have back.  As John says it's a wiring exercise.  The 2 bulb wires go to the 12-pin connector that plugs into the main circuit board.  Look at the diagrams that come with an upgrade which show you exactly where.  I'd think the biggest hassle is finding those crimped wire(s) that snap into the 12-pin connector housing.

What about using parts from a dead board for the wire with the pin.?

Mort

Sounds like a plan.  In case it's not obvious you bend up the plastic retention clip like a diving board with a hobby knife or whatever to pull out the crimped wire.  The photo shows the 2 locations where the rear-light goes to.  The purple wire is undoubtedly in the housing already so you need to find a place to tap into that wire.  Depending on your engine this wire may go to another circuit board or connectors where you can pick it off, or you can splice into the wire, or whatever...in other words a wiring exercise.

Thanks for the help and ideas.

Mort