If I followed your posts correctly, the last corrective action was repairing
a corroded wire and that seems to have solved the problem, is that correct?

Disclaimer: I am not an A&P.

I am a part of every repair decision made to my plane. I respect and trust
my mechanic. He does good work and is well respected by a lot of people. But
I know that I am but one, thankfully infrequent customer and he has other
distractions. If the explanation doesn't make sense to me, the repair
doesn't get done until it does. It's a classroom for me and I want to learn.
If I go along with a goose chase, I consider it as much my fault as my
mechanic's. Sometimes, a goose chase is the only approach. Sometimes it's
the easiest. Rarely is it the cheapest. As long as I go into it eyes wide
open, I'll accept the consequences.

The sequence of your events don't seem right. It throws a belt. The theory
is that crankshaft vibrations are causing it. That seems like the least
likely cause but, OK. Replace the belt. It gets thrown again. Why does the
diagnosis now change to be regulators and alternators. That seems to
indicate wild guessing - and, in fact - fickle, wild guessing.

Unless you threw him the keys and said something like, "I don't care what it
costs, just fix the problem," you deserve a break. My mech usually splits
the labor cost of goose chases until we catch the goose. If he declares the
problem but then has to re-fix and re-fix, he bites the bullet.

If this is your regular mechanic and you don't want to cause a scene, just
remind him of it over the next couple of repairs and see if you can coax
some good will out of him.

-------------------------------
Travis
Lake N3094P
PWK

"Viperdoc" wrote in message
...
It is belt driven off the accessory case. One possible explanation was a
sticking crankshaft counterweight. However, the engine has not shown any
indications of vibrations, such as smoking rivets, cracked baffling, etc.

However, until the new belt was installed, there had never been any
problems with the electrical systems.

I suspect, but will never be able to prove, was that the belt was either
not tightened enough when changed, or the field wire was knocked loose or
kinked, causing the alternator to run intermittently. On inspection after
the fact today, it was corroded.

My standing there watching would not have made any difference- there would
have been no way to tell if the wire was broken, and short of taking the
wrench and tightening the alternator myself there was no way I could tell
if it was loose.

I ran the plane for nearly an hour after the work today, with none of the
same indications, including under a heavy electrical load with lights, etc
in relatively high IMC.

Hopefully, it'll be back to where it was prior to the inspection.