[Steeveedee]

If it is a diode, you MIGHT see a spark when you disconnect the wire. I could have been a little more clear about it. If you pull that wire off and the battery isn't discharged in a day or so, that is the problem. The rebuilt alternator I first got was noisy, and I suspected a diode- they sound sort of like a front bearing noise when there's a bad one, but I didn't think much about it until I went to start the truck a few days later and the battery was cold as a mackerel- 0 Volts. I wonder how much life was taken out of that battery by going flat like that. Guess I'll have to keep an eye on it.