Caitlin - not working - Talking James & More

Hi ... new here. I bought a tub of trains and am working on getting them up and running for my grandson. I've cleaned etc. a few just refuse to work. All wires are in place, gears look good. How do I tell if it just needs a new motor. I have one I would love to get running ... Caitlin and her cars. I also got a Ferdinand with cars and he is just lovely... runs great.

I got Percy running although slow; no hair or gunk. One Thomas runs, one does not. These are all from about 2009 - 2012. Have new batteries in all. Not sure how to proceed; Caitlin's motor turns (not froze) ... Since I am an artist,musician grandmother I need some help




Thanks .. Victoria