Conversion: 6-Volts to 12-Volts
Someone wrote regarding the conversion of a
VW 6-volt electrical system to 12 volts - I know virtually nothing
about this conversion, so I would want to know a little about
it before I do it or have someone do it for me. I know that
it will effect many components, like the wiper motor, for instance
(as I recall). And I also know that there are some out there
who ask, "Why do it?"
Rob responded - The conversion from 6 to 12
volts is not hard. The 6-volt wiring is thicker than the 12-volt
wiring so can handle 12 volts without any changes. The fuses
need to be changed to 12-volt ratings though - mostly 8 and
16 amps (the 6-volt ratings are too high).
You need to change EVERY light bulb to 12 volts
including the dash lights and indicator lights (gen, oil) etc.
The regulator must be 12 volts (unless you are
going to use a 12-volt alternator with internal regulator in
which case the external regulator can be removed altogether).
The wiper motor will work at warp speed and
overrun the auto-park feature unless you reduce it's speed.
Some folks use a high-amp resistor, but this gets really hot.
There's a neat little current-limiter circuit on our web site
which works MUCH better. See our article on Running
Your 6-Volt Wipers on 12 Volts. The circuit has only four
components and can be made by anyone who can use a soldering
The starter motor can stay at 6 volts - it will
work very well on 12 volts, spinning the engine faster, and
it won't overheat unless you crank for long periods.
The fuel tank sender might need altering too
(e.g., the 12-volt sender may not fit).
is certainly a guru with VW electrics, and his site, Speedy
Jim's Home Page, has a wealth of useful information - worth