8V92 alternator questions

[sfedeli3]

Hi Don,

I also have a Prosine 2000. When both the generator is running and
the engine is running with the Prosine charger enabled, the readings
will fluctuate wildly because the Prosine is "sensing" the alternator
output, thinking that it is an overcharged battery and the voltage
regulators in the coach's alternators are "sensing" the Prosine's
output, thinking that it is an overcharged battery and are stepping
back their charge voltage. Running down the highway, with the Prosine
charger disabled, I see voltages of 12.8 to 13.4 volts on the Prosine
readout, indicating proper alternator function. I would not run the
Prosine charger with the coach running, unless your voltages are
dropping below 12.4 volts on the coach alternators and you truly need
the 12V+ power. Forgive me if I missed something in one of your
earlier posts- I just came across this thread yesterday.

Shane Fedeli
85PT40 "Bella Vita"
Hershey, PA

. --- In WanderlodgeForum@yahoogroups.com, "Don Bradner" wrote:
>
> I am home now, and will hopefully have a couple of months to get
things ready for the next trip. I had an "interesting" day, and will
outline it while the data is fresh in my mind.
>
> We started the day in sporadic rain, that progressed to steady rain.
Early on, when I would turn on my headlights, the transmiission would
flash "Do not shift" and "Check transmission", 3 blinks, then off,
then repeat in a few seconds. That would end with turning the
headlights off.
>
> Later in the day, when the headlights were on all the time, the
transmission did not complain.
>
> With headlights off, I had voltage readings typically like:
>
> Analog gauge, 13.2 volts
> Prosine 2000 monitor, 13.4 volts drawing 8-10 amps
> Digital readout from the engine computer, regular jumping around
between 12.0 and 13.2, most around 12.5 and 12.7 (via VMSpc interface)
> Alternator 1 zero output, Alternator 2, 25 amps
>
> With headlights on, after being on some time:
>
> Analog gauge, 12.5 volts
> Prosine 2000 monitor, 13.0-13.2 volts drawing 8-10 amps
> Digital readout, regular jumping between 12.0 and 12.5, most around
12.0, 12.1, and 12.3. Occasional 11.8
> Alternator 1 zero output, Alternator 2, 50 amps
>
> Still with headlights on, generator running:
>
> Analog gauge, 13.2 volts
> Prosine 2000 monitor, 13.9 volts charging at 25-30 amps
> Digital readout, regular jumping between 12.5 and 13.2, most around 12.7
> Alternator 1 zero output, Alternator 2, 25 amps
>
> Conclusion: One alternator is not working, and the other is "weak."
Hard to say yet if the problems are with the alternators themselves,
or with connections to them. That will be part of the projects I have
to work on when it dries a bit (rain predicted for every day in the
next week).
>
> Don Bradner
> 90 PT40 "Blue Thunder"
> Eureka, CA
>