I did a search through the forum, but couldn't find the answer to my question. I recently won a brass SD-45 on eBay that I'm in the process of painting for the Burlington Northern and converting to DCC. The model has classification lights on the nose and rear of the long hood. I'm going to set the classification lights up on their own function. The question is, how were they used? Were they always on? Were they directional? I'm using grain of wheat bulbs directly in the lens openings with the appropriate resistors. A friend of mine detailed a circuit for the lights. I just need to know how they functioned so I know how to wire them up. Thanks in advance.