The generator is missing some starting current from alternator light to
be able to produce electrical power during first time after motor start.
On high rpm there is sufficient self-inductance from remaining static
magnetism to produce enough electrical power for voltage regulator.
That's the point where alternator voltage jumps to 13.4V. Probably you
have to replace your alternator light bulb or to check related wiring.

Regards
Helmut

'80 Vanagaudi

On 28.01.2024 20:25, Markus Benne wrote:
> I've noticed a behavior where the alternator will not charge the battery (and no alternator light is on) until I hit a high rpm.    Then I hear a relay click and the voltage jumps to 13.4ish volts and the battery is charging normally.
> My usual suspects are bad ground and/or a bad relay.
> Someone hit this before?
> Thanks,...Markus