PS-2 Dim Steamer Headlight

The MTH product number would be useful here.   I'd first determine why it's dim.  It could be a loose connection, or the bulb is out of position.

Sorry, you're right. I should have included that from the get-go.

The engine is 30-1518-1

https://www.mthtrains.com/products/30-1518-1

I've taken the shell off to look. At first, the headlight wasn't working at all. I gave it a wiggle to tighten it and now it illuminates... its just very dim.

That model has a single bulb.  It could be that the previous owner replaced the bulb and used a 12V bulb instead of the correct 6V bulb.  If you take the bulb out and power it from a 6V power source, you can see how bright it is with with the power that it's getting supplied by the electronics.  If it's bright with 6V, something else is wrong.  If it's dim with 6V, it's the wrong bulb.

This is the correct bulb for that model, it's available on MTH Parts & Sales.

@gunrunnerjohn posted:

That model has a single bulb.  It could be that the previous owner replaced the bulb and used a 12V bulb instead of the correct 6V bulb.  If you take the bulb out and power it from a 6V power source, you can see how bright it is with with the power that it's getting supplied by the electronics.  If it's bright with 6V, something else is wrong.  If it's dim with 6V, it's the wrong bulb.

This is the correct bulb for that model, it's available on MTH Parts & Sales.

So I took the Bulb out and connected it directly to 6v. It was still quite dim. It starts to get reasonably brighter at 9v + so it might be the wrong voltage of bulb.

Will any 6v bulb with the same size screws work? If so, I can go to a local electronics supply store and most likely find one for way cheaper than ordering MTH parts up to Canada.

If it's a 6V bulb with the small base, it should work.  The one thing to check is the current draw, I think the MTH bulbs are 60ma, but the lighting outputs can support at least three of them.