Is this not the "Cherokee oscillating Ammeter" thing? Mine has it. Exact
same symptoms. Had it for 11 years and 4 different alternators. Either the
split master switch (alternator side) or the alternator breaker having a
high resistance connection (either the wires or the switch/breaker
itself).

Google it. You should see lots of hits. A common problem if I recall.

It may be -- but it just started happening in mine. *Something* had to
change, and the fact that my mechanic was digging around in the magnetos
last week seems to point to the all-to-common "mechanic-induced" squawk.

Or, it could be the sudden, severe cold? Or, it could be coincidence.

Next nice day I'm going to de-cowl the engine and tighten all electrical
connections. That has cured other electrical gremlins for us...and it's
cheap!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"