Voltage too high

[vince1]

Voltage at the battery on this original system is reading close to 17 volts. Generator light works normally. Alternator output goes to the horn relay junction and then over to the battery as it should according to wiring diagram. I've tried plugging in a spare regulator with similar results. I have a spare 10si and CS130 but prefer to figure this out before using either of them.

If the blue and whatever other (I am not at the truck right now) wire at the alternator were reversed would that put it into a full charge situation? Any other ideas? Thanks.