Diodes don't fail real often. When you get a replacement generator, a new one would be horribly expensive, so you always get a rebuilt unit. Since those diodes don't fail often, and since they're relatively difficult / time-consuming to replace, they don't get replaced. That means even though your generator is only six months old, it has parts in it that are original. Normally just the brushes and bearings are replaced, and everything else is reused.
Diodes can fail anytime but it's more likely to occur when they get older. That's what your symptoms point to, but don't take my word for it. The load test will tell whether I'm right or wrong.
Monday, November 23rd, 2015 AT 6:28 PM