Just bought a 1972 Series 3 88 and I would like to know how the two sets of red lights on the rear are supposed to work. The outside lights come on when I press the brake or when I turn on the lights. One outside light goes off when I press the brake with the lights on. I have yet to find a switch or condition that makes the inside lights come on. I have checked all the bulbs, and I have confirmed that there is continuity to ground.