After a lengthy search I discovered that there were no simple wiring diagrams for the BU series.
Since the light is one of those 12v things from my 1972 Fiat Spider it requires the transformer to drop the 110v to 12v
Here are photos of both the Nora and the Miranda.
The light is chassis grounded so there is only one wire going to it
I removed the auxiliary outlet on both because the cord was deteriorated.