While I can't speak for all Steam-Along Thomas', I'd say the problematic areas are the battery compartments and the usual coupling between Annie and Thomas. Of the two Steam Thomas' I've owned, both have had completely wrecked battery compartments that were extremely corroded to the point where I had to completely replace all the contacts. One of them came with Annie's lower battery removed but the two upper ones still in a leaking, so it's also possible that it was bad batteries that someone didn't know where there and not the water that caused it.
Either way, I can't really recommend anything more then what everyone else has said. If the battery compartment has to be replaced, a voltameter may be useful more to make sure that power is getting where it should then how much is actually getting there.
Either way, I can't really recommend anything more then what everyone else has said. If the battery compartment has to be replaced, a voltameter may be useful more to make sure that power is getting where it should then how much is actually getting there.
I have a website where I have been writing about and photographing many of the sets and pieces that I find interesting.