I just made the suggestion to replace the bulb (a good one in fact) as a preventive maintenance, they are 20 years old if they are original. We all suggest to do the same with the fuses, replace them even if they are not bad to avoid the overheating problem the fuse block has with dirty contacts on the fuse blades. Also I don't believe the "no bulb" or "bad bulb syndrome" hampers the OEM alternators. If I'm wrong correct me here. I think it has to do with the way it's wired up AND the new regulators that are in the new alternators. They need that "sense" that the bulb sends to them. I don't think the original alternators regulator really cared about it. Steve -