i have a 1981 380sel mercedes. where the gauges are located the turn signals (both) light up when i turn and when im low on fuel, the light goes on to tell me so. the problem is when i drive at night i cannot see how fast im going (all 3 gauges). so is there a switch i have to flip to make it light up or is it supposed to light up automatically when i turn my head lights on? i replaced 3 fuses today and still nothing. off the top of my head i dont remmeber which it was i replaced but, any ideas why they dont light? maybe a busted bulb? i have no idea how to open it up to replace the bulb. this is my first car and im learning as i go along. thanks in advanced.