Marx made several variants of its Girard station. One was just a tin building. The better one had lights. The best one had lights and a train whistle. Here’s how to wire a Marx Girard station with both lights and the whistle. This works on the Oak Park station too.
I wire it a little bit differently than Marx did in its instructions. Marx’s way works, but can cause the light to dim when you push the whistle button. My way doesn’t dim the lights.
The Marx Girard station with both lights and whistle has three posts. Before you do anything else, you need to determine which one is common, which one is the whistle and which is the light. The Oak Park station wires up the same way. The difference is the Oak Park station has a horn rather than a whistle.
Mapping out the posts
When you flip the station over, the common post won’t have a wire or insulating washer on it. It’s just a bare screw attached to the base.
The center post is probably the light. I say probably because if someone ever serviced the station, they may not have put the wires back where they started.
If you just can’t tell, run wires from the transformer straight to the station. Connect to any two posts. If nothing happens, change one of the wires to the other post. The new post is common. Note whether the light or whistle activates. That’s what the other post controls. Move the non-common wire to the other post to verify the other function works.
Run a wire to the common from the base or common post on your transformer. Next, run a wire from the hot accessory post to the light. Run another wire from the hot accessory post to a pushbutton. Finally, run another wire from the other terminal on the pushbutton to the whistle post.
If you don’t have the original button controller, you can use a cheap doorbell button from any hardware store. A basic doorbell button should cost around $4.