Originally Posted by
noglider
.....
I'm under the impression that the new stuff doesn't ground to the frame intentionally but might accidentally so that would be one reason you have to keep track of polarity. Is that right?
I haven't opened up a commercially built light in a while.
Some B&M tail lights that I've worked on in the past had one mounting bolt attached internally to one electrical terminal. No idea if they've changed that practice or not. There was usually a small chassis ground symbol molded into the plastic to indicate which terminal was grounded, but it wasn't easy to see and could be overlooked by the average consumer.
In case I haven't mentioned it lately, I make my own dynamo headlights and tail lights, so don't get exposed to the commercially made stuff very much.
I wouldn't expect to see accidental connection of a terminal to the frame, though.
Steve in Peoria