Robert M. Gary wrote:
I have a 70amp alternator in my Mooney. I find that when I turn on
the
landing light, the voltage drops down to around 13.0 volts or less.
During off the landing light brings it back to 14.5 volts. The Mooney
Factory Service Center is telling me this is normal. They said Mooney
didn't design the plane to fly around under the continuous load of
the
landing light.

Opinions??

-Robert

Mooney should be ashamed of such a statement. I will wait for your
answer to "where did you check the voltage" but for a thorough reply,
where did you measure it, what else was on (what was the load on the
alternator) and what lamp (s) are we talking about? 4509 or Q4509
type require about 9 amps each. If you are measuring at the lamp, I
would expect the drop you saw.

Neal