ALTERNATOR OUTPUT

67Dart273 said
When you unload an alternator and full field it, the voltage goes to the moon

So that might answer how the OP could be getting 26 volts at the alternator.

If the output from the alternator was not actually connected to the battery (through any of the typical ways)

And the voltage regulator was seeing low battery voltage because the battery is not being charged.

Maybe it could get to the magic 26v?

Just a thought!