"Robert M. Gary" wrote in message
oups.com...
When I turn on a lot of accessories on my Mooney F '76 I can drop the
bus voltage down to around 13.6. My A&P says 13.6 is normal with
accessories on. Does this sound right?

-Robert

At cruise RPM? Sounds like you may have 1 or 2 of the three diodes burnt
out in your alternator. Another possibility is that your voltmeter is off.
Try checking it with a digital voltmeter, and comparing the two.
--
Jim in NC