Behind the front and middle wheels are thin pieces of metal that attach to the rail contact “feet”. They allow for electrical continuity to occur on both wheels.

I do not have a manual, and don’t know what these parts are called. Hopefully someone knows what I am referring to.

I admit that the problem was caused by my negligence. I did not service the car before using it this year. Some bolts got loose, and other parts needed grease. On top of that, I tested the locomotive on an outdoor LGB track rather than setting up the Gauge 1 track. The LGB track was too bumpy for this locomotive.

My other question has to do with a switch inside the cabin. It is a simple 2-way toggle switch with “I” on top and the down position is “O”. Does anyone know what this switch does?

If anyone knows how I can order parts for this locomotive, please let me know. Thank you.

This is a link to a loco similar to yours ( I hope the link works ), none of the spare parts are available from Märklin;
but you can at least find the German name for the parts you need, which can help you:

https://www.maerklin.de/...elnummer=5450&lang=2

The switch is as Pål wrote on/off for the smoke generator.

Per.