6 Volt Bus Conversion to 12 Volt Charging Notes
by Joe Fournier
There was generally agreement on the following
points regarding a conversion to 12v from 6v (though not all who responded to the mailing list poll
addressed all points):
For many items, such as the clock, voltage drops can be used.
- Wiring - doubtful that any wiring needs to be replaced, as 6v systems
tend to have more amperage pumped through them than do 12v systems. amperage
is really the deciding factor, so I infer that a 12v replacement that draws
more amperage than the origian 6v item probably warrants consideration of
whether the wiring can handle the change.
- Bulbs - will be very bright and hot for a short period of time, then they
will cease to work. I infer that there's a small risk of damage to nearby
stuff as the bulbs overheat (don't forget the e-signal bulb).
- Fuel sender - does not need to be changed; it's a resistive element and
the same elements were used in 6v and 12v units.
- Fuel gauge - there were different gauges for 6v and 12v buses. Dave
Easterwood is certain you can run a 6v gauge in a 12v bus; another
respondent (Justin) confirmed that he runs a 6v gauge and sender in his bus
and it works fine. Lucky for me, I have a spare 12v gauge, so it's a non-issue.
- Clock - running a 6v clock on 12v will fry the points in the clock. (If
you've never seen the inside of a VW/VDO clock, they're simply elegant. They
really are wind-up clocks, wound every couple of minutes by a set of points
making contact. I picked one up at a junkyard a few weeks ago and was able
to fix it in less than an hour of tinkering (though I'd never seen the
inside of one before). I ain't no Eisenstein, they're just that simple...and
There are lots of other things I didn't ask about because I think I know the
answers. Please correct me if you know I'm mistaken:
Wiper assembly - 6v runs very fast, putting extra stress on bushings and in
many cases eventually frying the assembly.
Starter - 6v winds up fast, but again, often dies an earlier death if run on
Radio - 6v run on 12v would fry almost immediately. Use a voltage drop or
upgrade to something better than an AM radio. ;)
Switches - shouldn't have a problem, except if they have bulbs, which need
to be changed per above.
Generator - specific to 12v or 6v - don't interchange.
One more thing...I THINK I can run a 12v radio by tapping juice from 2 6v
batteries in series. I know I'll have to do this in such a way as to isolate
the power between them, but I think this is similar to the issue of how you
run an auxiliary battery. Since I have a 6v gas heater that I'll consider
installing at some point, a second battery is a real likelihood for me.