Low volts and amps; was alternator

[freewill2008]

Jeff - How did BB accomplish the 'external voltage sense' with L-N
alternator? Is the external sensing point the place to put the
voltmeter when adjusting the L-N regulator?

Also, a general comment: When an electrical problem seems to be due
to the length or size of a cable, remember to check the
terminations. Crimped-on lugs do NOT get better at conducting
current with age. Same is true where a lug fastens to a terminal.
If in doubt, install new lugs and clean all contact points until the
metal is shiny. Then apply a product like Rid-Ox before assembly.
Remember that each cable end is actually TWO connections: One from
cable to lug, and another from lug to terminal. That's FOUR points of
failure for each run of cable (True of ground straps also).

Bob Griesel

--- In WanderlodgeForum@yahoogroups.com, "Jeff Miller"
wrote:
> Hindsight is 20/20 isn't it?
>
> Granted the dash in your early '82 FC could have benefitted from
the
> addition of a few load-reduction relays: headlamps, ignition, A/C
> switches for example. Fortunately BlueBird figured that out many
> years ago also and made production changes.
>
> Your alternator and wiring also ended in late '82, all of the
3208Ta
> engines had the Leece-Neville alternator with internal regulator as
> original equipment. The external voltage sense was retained,
through
> at least the late '90s S-60 powered WLWB coaches, and was intended
to
> maintain proper voltage at the power buss regardless of voltage
drop
> over the wiring run. Many alternator folks don't understand this
> wiring and I usually see it mis-wired by now.
>
> Although the charger wiring is long, 1AWG is probably considered
> adequate for the original 90a peak charging current over perhaps
25'.
> Some of the battery wiring was upsized in mid-CY-1982 with the
> addition of the battery isolator next to the slide-out battery tray.
>
> I'm not sure that 4/0 battery cables for the 18" from battery to
> junction would be practical (or necessary). Perhaps a jump to 1/0
> would be more manageable? Trying to use the slide-out battery tray
> with 4/0 wires would be difficult and other than starting current
> there isn't anything that normally will cause significant voltage
> drop in that wiring.
>
> - Jeff Miller
>
>
> --- In WanderlodgeForum@yahoogroups.com, Tom Warner
> wrote:
> > FC models are saddled with two engineering design problems.
The
> first is
> > that to much current is running thru the dash and the second is
the
> very
> > long cables between the chargers, the alternator and the
batteries.
> The
> > more current you can divert from the dash, such as using Bosch
> relays for
> > the lights, relays to get the A/C current(driver and passenger
> sides) out
> > of the dash, etc. Change the battery cables to 4/0 although not
the
> best
> > fix nor the optimal condition, it does seem easier then to change
> the
> > chargers to the passenger front bin. One more problem is that the
> FC models
> > were designed to use the motorola alternator and an external
> regulator that
> > senses the voltage directly across the batteries. Most people
have
> changed
> > that out to the Leece_Neville with the internal regulators which
> cause a
> > problem.
> >
> > Tom
> > 1982 FC35
> > Vernon Center,NY