Can I convert an HO scale passenger train so that its interior lights up?

Question by VGFan: Can I convert an HO scale passenger train so that its interior lights up?
I recently purchased an HO scale Metrolink and was able to get it open and glue some sitting figurines in some of the seat, they are difficult to see and was wondering if I would be able to add lights to the interior of the passenger cars. If this is possible could you possibly post a link to some auctions on eBay that have these for sale. Even a store website link would be great just so I know what it is exactly that Im looking for.

Best answer:

Answer by mike1942f
Simple answer – install a D cell or a couple of AA’s and put a couple of white LED’s along the roof. The 1.5 volt batteries can run LED’s without current limiting resistors. Switch in bottom or open to turn on and off.
Messier answer: change out the trucks (unless the Metroliner cars are already self propelled.) to insulated axles with conducting wheels to provide power from the tracks to the car. Collect the power, regulate it, buffer it, and feed it to grain of wheat bulbs or LEDs.

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Cityrail train interior

Cityrail train interior
electric train sets
Image by brianapa
The Millennium train or M Set is a class of electric multiple unit operated by CityRail in Sydney, New South Wales, Australia. It is one of CityRail’s newest members of the fleet and was the first "4th generation train" on the network.[1] The trains were put into service from July 1, 2002[2] after a small amount of testing and replaced ageing 1960s Tulloch trailers, all of which were withdrawn by March 2004. The trains can operate over the entire suburban network, though they normally operate in sector 2.