The low fuel light does not work on my 89 300E. I've read that it is supposed to light dimly when starting the car, but it doesn't. I took the sender unit out of the tank, took it apart and cleaned it, making sure that the contacts on the float touch the contacts on the base. No change. Is it possible for this light to burnout? I haven't found any information about changing it. The MB Shop Manual CDs don't have anything about it, except to show a light on the wiring schematic. Anybody with knowledge or experience?