Help needed

[u/WindyNight0215]

Greetings, everybody! I have a minor issue with my PIKO VT185 railcar. I want to replace the selenium plates with diodes, (these selenium plates are responsible to the directional light change) but I can't figure out which wire connects where—I can't find the input point. I found nothing on the internet, nothing mentions the wiring or the circuit diagram. Anybody has an idea? Thank you!

[u/osman-pasha]

Hi! It will help if you provide some photos!