More battery/voltage help needed

[Jeff Miller]

It is not uncommon to have batteries less than fully charged when
newly installed, in which case the alternator might initially have
trouble maintaining >14v until they are substantially charged. Old
batteries might not have had the capacity to draw much charging
current.

As the batteries become more fully charged, the voltage should climb
up. If your ammeter is working properly, you should be seeing at
least 60-80amps to draw the voltage down that low (assuming little
12v draw from coach systems). If not, it would appear that your
alternator is getting weak, if a diode is bad you will have reduced
output, or a regulator problem. Is it the original Motorola?
Internally regulated? I believe that the original internally
regulated Motorola has an adjustable output (large screw-slotted
shaft sticking out of the back of the alternator).

The original gray-box chargers are also sneaky. They will hum as
normal when they don't charge. It is very common to have only one
charger functioning and not know it until the other fails.

A replacement 160a Leece-Neville (I think A000128??) J-180
replacement alternator can be found at any heavy-truck dealer for a
reasonable price.

- Jeff Miller
in Holland, MI


--- In WanderlodgeForum@yahoogroups.com, "Scott Forman"
<sforman@r...> wrote:
>
> OK guys...I need more help.
>
> My coach now has four brand new T105 batteries. With my engine
> running at "high idle" (about 1200 rpm), a multi-meter reading at
the
> alternator reads 13.6. This is also the voltage shown at the
> batteries with the engine running and at the voltage gauge.
>
> Is this normal? Before I installed the new batteries, the voltage
> gauge usually registered above 14 when running. Is this because
the
> new batteries are new and require less output?
>
> I am asking all this because it seems like these new batteries are
> not as strong as the old ones "at rest", leading me to wonder if
they
> are not being charged enough while the engine is running.
>
> Thanks,
> Scott Forman
> 82 FC35RB
> Memphis
>