I've amassed quite a collection of FA and and F3 locomotives and dummies. The downside is I haven't been able to get the whistles to work in any of them. I've tried several batteries, so I don't think that's the issue. These are all older locos and the whistles are apparently not known for robustness, but some of these locomotives are in very good condition otherwise. I'm using a 1033 transformer. Any ideas on things I should check?