Now
we were ready to mount the alternator to  the
engine. Simple enough as the new alternator mounting bracket
uses the very same mounting as the generator bracket we
were replacing. With that done it was time to wire the
alternator. There are just two wires to connect. The “Batt” wire
from the old voltage regulator connects to the 10/32 stud
on the back of the alternator (see drawing).
The
yellow wire from the alternator connects to the battery
side of the ignition coil (this is the side of the coil
that receives power from the ignition switch). With these
two wires connected we were done! The instructions were
simple and straight forward. Our total installation time
was less than one hour. Our dim headlights are gone and
the truck starts much easier, especially when the engine
is hot.
The reason
everyone made the upgrade to a (12) volt system in the
old days was to get away from dead batteries and dim
headlights. These two common complaints were mainly the fault
of the way the electrical system was designed. Let’s
look further...
The generator
doesn’t begin to recharge the battery
until about 20 mph vehicle speed. Anything less and the battery
has to provide all of the electrical energy. When the car
does reach 20 mph the generator has two jobs. One is to provide
electrical current for what the car is now using, and the
other is to replace what was already used from the battery.
To put this in perspective, every time you start your
car with a (6) volt generator charging system...you
need to drive 10 miles at highway speeds to allow the
generator time enough to replace the energy used for
that one start!! |
To
understand this further we need to look at how much electricity
your car actually requires. Using a 1950 Chevrolet car
as an example, the ignition |
|
requires
(1.6) amps, the headlamps together (14.0) amps, taillights
(2.3) amps, dash and instrument cluster (2.5) amps, heater
blower motor (8) amps, factory tube type radio (7) amps
for a total of (35.4) amps. We must also add any modern
accessories such as electric fuel pumps or radiator cooling
fan.
 While
it is agreed not everything is turned on at any one time,
you must also remember that the generator
has little or no output at an idle and the (30) amp output
rating of the generator is based on the speed the generator
is turning at highway speeds.
Proof
that this is indeed your problem can be determined by checking
the voltage
at the battery. A six volt system should have a minimum
of (7) volts at the battery just as a modern car will
have between (13) and (14) volts at the battery. This
is to
ensure that all of the modern car’s accessories
will be powered by a full (12) volts.
If
you have (5) to (5.5)
volts in your 6 Volt battery (which is common with
a generator charging system) it is easy to see why
your
head-lights
are dim and you always have a dead battery. The actual
problem—as we have discovered—is not
the 6 volts, but rather the lack of it.
And
it is easy
to see
that an (8) volt battery will not help, after all
we can’t
recharge the (6) volt battery we have now, so how
would we recharge an 8 volt?
A
(12) volt generator works
the same way as a (6) volt generator. It does
not charge at idle and low rpms either. In the old
days, by upgrading
to (12) volts the amp load was reduced. This
can be easily
understood, if you remember one of the basic
rules of automotive
electricity that says...
 If
you double the voltage or (electrical pressure)
the amperage required to do a given job is reduced
in half. In other words, if your (6) volt headlights
require (14) amps from your (6) volt electrical
system, they will require only (7) amps if the
system is upgraded to (12) volts. |
|
|
