Jim, you are a BAC member (I think). Please do a BAC search (upper right corner) on the words "discharging battery problem", without the quotes. You will find everything you need to know, including the fact that people are working on your alternator who apparently still do not know how to troubleshoot intermittent (and solid) alternator problems. Bob Steward and I have addressed this same issue at least two dozen times so far, on both BAC and MML, and it is well documented in the FAQs on the BAC website (and the MML Archives).

Unless you have two alternator circuit breakers (a five-amp and a fifty-amp), your alternator switch (actually the alternator field switch), is NOT a common Radio Shack switch. It will be a special switch that incorporates a five-amp circuit breaker. It is true that they can go bad. If you want to continue down the road of parts-replacement diagnostics, feel free, but these switches don't have a Radio Shack price. The current carried by the field circuit is rather small; always well under five amps even at full output. The only high-current alternator "switch" is the 50 amp circuit breaker itself.


----- Original Message -----
From: Jim Campbell
To: musketeermail@yahoogroups.com
Sent: Monday, August 15, 2005 10:24 AM
Subject: [musketeermail] Special Alernator Switch?


We have had a lot of problems in the charging department for a few
months. The alternator was removed and overhauled six months ago but
we have had intermittent instances of 'no charge' or 'low charge'.
Just after the annual last month we ended up with a dead battery, went
back to the shop and they said an alternator wire had come loose or
some such.
We got it home with a really strong charge indication but next weekend
no charge and a dead battery after a short test flight. We replaced
the battery with a new fully charged one but still no charge from the
alternator.

Our repair man now suggests that the alternator switch may be causing
the problem. He claims that it incorporates some sort of fuse or trip
mechanism that may have failed. Is this b/s?

I can believe that after all the years handling what must at times be
a very large current, the contacts may be pitted somewhat But I find
it difficult to believe that the switch is anything different from
what you can buy in Radioshack. We believe it to be the original
equipment (s/n MA-314)
Jim Campbell
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