No disagreement. I said that the switch was not a breaker-switch if he has two separate circuit breakers for the alternator (a 5 and a 50). And as far as I know, all the alt field switches are in series with the Master; i.e. no field power if the Master is not on (along with the Field switch). If it is a CB switch, it will have a number on a small flat area, on the end of the toggle handle. If no number, it is a non-CB switch.

Regardless, you don't want to replace the DC-rated switch with a run-of-the-mill Radio Shack AC-rated switch. The internal contacts will not hold up to the DC flashover. Most of the non-CB Beech switches are two parts; the switch and the handle cover. I guess that enabled them to use different trim in different planes, while retaining the same switch unit. To tell you the truth, I have never tried to remove the cover on a switch, once installed, so I don't know whether they are transferable.

----- Original Message -----
From: ke4oh
Sent: Monday, August 15, 2005 3:26 PM
Subject: [musketeermail] Re: Special Alternator Switch?

I don't want to disagree with Bob and Mike, but I think in this case
I think it's possible they may be incorrect.

Jim, you indicate your serial is MA-314, which is a late Super III. I
have MA-170, a Super a bit older than yours. The alternator switch on
mine does not have a built-in field breaker. I have a seperate 5 amp
field breaker on the panel. Mine has an alternator switch and a
separate master (battery) switch. These switches are wired such that
if the alt switch in on but the batter is not, then nothing happens.
Like the "split" master switches common on Cessnas, only this is two
discrete toggle switches. Both these switches have the same part
number and are heafty double-pole double-throw units (though only a
single set of poles is used on the alternator switch). I learned all
about this when my battery switch went intermittent. I verified that
the wiring is as I described in the Beech parts manual. At the time
(about 2 years ago), Rapid was getting about $40 for one of the
switches, less if it didn't have the decorative chrome thingy over
the standard chrome toggle. (Guess which one I bought!)

Something to try: Your alternator switch has an unused set of
contacts. Try moving the wires to the unused set. This might save you
the cost of a switch.

Sincere apologies to Bob and Mike if I'm wrong on this.

Best regards,

Steve Robertson
N4732J 1967 Super III

--- In, n76lima@m... wrote:
> >Our repair man now suggests that the alternator switch may be
> >the problem. He claims that it incorporates some sort of fuse or
> >mechanism that may have failed. Is this b/s?
> >I can believe that after all the years handling what must at times
> >a very large current, the contacts may be pitted somewhat But I
> >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
> Its most certail better than the RS switches sold TODAY.
> Most of the early Musketeers used a combo switch circuit breaker.
Its possible that it is popping in flight. And who can complain when
their 35 year old switch goes bad? Some items like this are due to
be replaced because of AGE.
> An easy test is to check the output side of the switch wit a meter
next time you are getting no charge. THe Alternator "Master" switch
is really just supplying power to the voltage regulator, and if there
is no power on the output side, that kills the voltage regulator, and
leaves you with no charge fro the alternator.
> A 12V est light or a Volt-Ohm Meter is all tat you need. Engine
need not be running. Flip on the battery master and the the
alternator master check for voltage.
> --Bob Steward A&P IA
> Birmingham, AL

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