some light on odd electric issue

[Pete Somers]

GMAs
It is not my intention to talk out of turn here but I will make some comments on your trouble shooting ideas, and the little quiz.
I do not think a simple volt meter is good enough to start measuring voltages and resistance as they are not accurate and libel to errors. As i have seen when measuring across a circuit breaker you will need to load it as a bad connection inside the breaker would not show until loaded.

On the '65 337 both alternators are fed by one regulator so you cannot compromise between the front and rear, so any oscillation problem are down to wiring, connection, and the condition of breakers etc. On all 337's with dual regulator system this is not a problem as each regulator output can be adjusted to suit.
By the way GMAs what should be the voltage at the alternator field on a '65 337 and just for fun what should it be on the '77 337, just a little quiz for you all.

You seem to go a lot for the master or starter relays, and your failure rate seems high and over here we have 30-40 year old aircraft flying quite ok and never had a relay go down. Most of the Cessna range use this relay with no problems.

Change a battery after 2 years, no way, to expensive and not necessary if the battery is maintained properly.

I do not understand your shotgunning is not an acceptable method, please explain.

These are just my thoughts and would be interested in the reply/comments.

Cheers
Pete