Re: [MV] M35A2 Generator

Edward Greeley (
Tue, 28 Jul 1998 00:43:04 -0500 wrote:
> The volt guage in my M35A2 recently began going into the red, to the right of
> the green area. Does someone know what this means? Am I overcharging > my
> battery?

Quite probably. Is the battery "water" (electrolyte) disappearing faster
than usual? That would indicate a higher than normal charge rate.

Note: I assume with my comments that your engine starts normally,
without use of a "boost" from another battery bank or charger. If that
assumption is correct, then you probably do NOT have a battery or wiring
problem which could cause the abnormally high voltmeter reading. In that
case, the problem is probably a failed regulator.

> Is the voltage higher than 24?

Very likely. Are your headlights, for instance, abnormally bright when
your voltmeter is in the red?

> Is my guage bad?

Very unlikely. The usual failure mode of voltmeters is to read zero, or
some voltage lower than it's supposed to. In 50 years of
electrical/electronic work, I can't remember a low-voltage voltmeter of
the type in question ever failing so as to suddenly read higher than the
actual voltage. My suggestion is to beg, borrow, or steal a digital
volt-ohmmeter and check the voltage at your battery terminals when your
engine is running at the speed which causes the vehicle's meter to read
abnormally high. The battery voltage at full charge rate should not be
above 28 volts max. (across both batteries, of course!) As a last
resort, if you can't get a digital meter otherwise, go to Radio Shack
and buy a cheap one for $40.00 or so. Anyone who works on old vehicles
will find it very convenient to have one after learning how to use it,
which isn't that difficult! You want a DIGITAL meter, NOT an analog (one
which has a pointer on a scale) meter for accurate, meaningful voltage
Hope that's a little help!

Ed Greeley
Mobile, AL

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