[willimo]

I don't know what motivates you to want it on a timer, and it may just be because you want it that way. But instead of a timer, you could use a reed switch. A reed switch is a small switch that uses a magnet passed over it to open or close a circuit, and is often used by model railroaders to activate trackside animation when a particular rail car passes over a certain spot (the switch would be buried under the track). Using a switch such as this, you could turn the lights on and off without having a switch poke out or having to touch the car at all. Just an idea. And I would be very curious to see what you find out as far as this circuit goes, because I don't know squat about electronics either.