Subject: 6V to 12V

[Jim Shepherd <beltguy@domain.elided>]

Lets take another look at this subject.  Some have used the equation E=IR
and have concluded that you get twice the amps.  That statement is true for
the maximum wattage *capability* for a given circuit.  However, whatever is
in the circuit has a wattage demand.  For example, a headlight might take
75 watts.  Here, the equation Watts=volts*amps applies.  Thus if you double
the voltage, you half the amps.  Obviously, with half the amps for every
circuit, the wire is very well sized.  The only reason to change is if the
insulation has gone bad.

We used to change the 6 volt systems all the time in the old days.  Most of
the gages work just fine on 12 volts.  The starter will work just fine as
long as you don't crank for very long periods - spins nice and fast.  We
used to change all the bulbs, put a volt-a-drop on for the radio, change
ignition coil, add a balast resistor (no need to do this with the new high
voltage ignition systems - MSD et al) and call it a day.  On of the real
benefits is that the horns really sound neat (loud)!!

Jim Shepherd
1986 S1900 being made into a motorhome
1959 BC150 project truck

>>>>>>>>>>>>>
>
>We got this answer:
>> If you increase the voltage by doubling it, you've doubled the current.
>
>And this answer:
>>increase the voltage you decrease the amperage. Theoretically, you could
>
>As just a standalone statement, Joel's is correct.  But I think the
question was about a conversion of the "sinks" (the gauges & lights) along
with the source (battery/alternator).  So, for the simple case of a light
bulb of equal power, a 12V bulb will need half the current of a 6V bulb.
And so the same would probably apply to a gauge.  But if you don't replace
the "sinks," you'll either burn them or the wiring up.
>
>So when the context of his answer is considered, Dan is correct.
>
>