8V92 alternator questions

[Bob & Carol Howald`]

Don: A few years back on my 93pt I had a problem. When I would
flash my head lights (bright to dim etc) I would get a TRANSMISSION
DO NOT SHIFT LIGHT. I cured it by cleaning all the ground strap's on
the engine and transmission. I used a battery powered wire wheel,
took them all off and wire wheeled each one. I also added a couple
more strap's . It also cured the speedometer from reading 15mph while
standing still. AS far a checking the alternator's, just take a 9/16
socked and disconnect the alternator lead's from the main bus, one at
a time and seeing what your voltage reading is. Going down the
highway I usually see 14.0 volt's on both set's of batterys and
somewhere around 25 amps or less on the charge meter depending on
condition's such a Day,night wiper's on, etc.
Bob 93pt-40


>
> Don:
> It does sound like alternator problems. Many times alternator
problems are not the alternators fault. I may get beat to death on
this but I would first check the ground strap from the frame to the
engine and the ground connection at the point where the battery
ground connects to the frame. If there is not integrety in both areas
you will have strange problems. I know you changed the batteries, but
I wonder if you have a floating ground? Weird stuff is going on. It
has been three years since I messed with mine , but I believe the
alternator ground wire connects to a bolt on the top of my engine.
If the engine is not properly grounded and the alternator is grounded
to the engine, it will not work properly and can also be a factor in
alternator failure. Just a thought, and it will not take much to
check it out. If it is the problem, then it saved you a lot of work
and time. Happy your trip was a safe one.
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Niceville, FL
>
>
>
> ----- Original Message -----
> From: Don Bradner
> To: WanderlodgeForum@yahoogroups.com
> Sent: Wednesday, February 21, 2007 10:07 PM
> Subject: [WanderlodgeForum] Re: 8V92 alternator questions
>
>
> 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
>
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