I just purchased a 1946 Lionel 671 smoke bulb locomotive. It ran when first tested although the gears were noisy and tight, meaning not moving very fast. After disassembling it I discovered that The motor mount screws were tight and binding down on the shaft (issue for another time). So after loosening the screws a little to see how it runs I think I shorted out a wire as it sparked where the wires are soldered to the brush plate (I think that’s what it is called). The locomotive was dead after that. Mind you everything was working, light, Eunit and motor besides the grinding. So I started jiggling wires and checking connections and couldn’t find the short. Thought I burned out the motor. So I disconnected the wires and tested the motor separately with jumpers coming from my KW, and it runs fine in both directions.
My question is I now have to solder/replace some of the wires as they are definitely the originals and are falling apart. What kind and size wire do I use?
thanks,
Art