I think I just figured out how the headlights are supposed to work. Model number from trim piece is from 1985 Cadillac...guess it was a good year for headlights.

I think the outboard lights are dim and always on...inboard lights are bright and turn off and on with the dimmer switch.

Is that right?

I was replacing headlights that worked but had water vapor showing...always thought lights from that era were both bright and dim same bulb...but when I got my replacement bulbs through Amazon I noticed they were marked DIM. So I guess they make a BRIGHT model too.

BTW I'm busy replacing big, rusty fog and driving lights with cool little LEDs...report soon. Also the back-up lights same thing.

Check out this