Just so happens that I am doing my lights on my 1948 Styled Model B right now. My lights are different from yours. I’m guessing here, but I think a farmer did some barn modifications to yours. None of my lights have wires soldered to the back of the bulbs. There is a spring in the back of the bulb socket that pushes a revit up against the back of the bulb. The other end of the revit has the wire soldered to it (not the bulb). The bulb socket is part of the reflector. The reflector is pressed against the light housing with the gasket and lense hoop. The light housing is then bolted to the tractor.
Electricity goes from negative to positive. Since these model Bs are positive ground, it goes from the battery through the wire through the bulb to the reflector, to the light case to the support post then to the steering wheel support and finally to the transmission case. Each connection must be free of paint, primer, and rust for it to work.
Of course, just to make sure, you can always run an extra ground wire from transmission case up through the steering support out to each light and around the bolt that holds the light on the post.
Lastly, when you get it working, I’d use some silicone grease stuff that they use in modern cars around the bulb socket to keep moisture out but still conducts electricity.
I hope this helps.
Electricity goes from negative to positive. Since these model Bs are positive ground, it goes from the battery through the wire through the bulb to the reflector, to the light case to the support post then to the steering wheel support and finally to the transmission case. Each connection must be free of paint, primer, and rust for it to work.
Of course, just to make sure, you can always run an extra ground wire from transmission case up through the steering support out to each light and around the bolt that holds the light on the post.
Lastly, when you get it working, I’d use some silicone grease stuff that they use in modern cars around the bulb socket to keep moisture out but still conducts electricity.
I hope this helps.