Roll-Monroe-Co

For my frankencommuter I have salvaged an old schwinn (prob. Union) bottle dynamo lightset with head and taillight.

Let's say that I want to make this work, regardless of how not awesome some readers might think it is.

Upon being pressed into service for the first time in 30 years, the taillight lit up brilliantly, but the headlight did not come on.

There is a single wire running from the dynamo to the front light. The socket appears to be designed so that the wire slips into the plastic socket and makes contact with the the threaded silvery cap on the bulb. When the bulb is inserted into the socket, the contact at the end of the bulb touches a contact at the far end of the socket, which I assume goes to ground in the bracket, which is attached to the stem.

I have tried replacing the wire with a new piece of wire with freshly stripped leads.

I have inspected the bulb, and the filament appears to be intact. I also tested with another bulb of the same type (also probably 30 years old, but bulb appears to be intact. Neither did this bulb work.

Should there be a ground wire coming from somewhere and going to somewhere?

What else might be wrong?

Thanks for any help you can provide.

Eric

Edit: I also made sure that the positive lead is not touching the ground contact in the socket.