Type Three Tuning Page -- Electrical

Color Wiring Diagrams at http://www.thesamba.com/
6 volt to 12 volt Conversion Tips
>We want to convert the 6 V Notch to 12 and I just learned that there 
>are 12 V cranks and 6 V cranks. The difference appears to be the 
>flywheel end of the crank. If I go for a 12 V crank then I have to 
>have a 12 V flywheel which is the same as on a type 1.

There is really no such thing as a type 1 flywheel, but there are both 6V 
(180mm) and 12V (200mm) flywheels, both of which were used in both types of 
cars. There is also a crossover flywheel, which has the 6V ring gear and takes 
the 200mm clutch. Whichever flywheel you use, you really should use it with the 
correct crank. There is one way that you can "mix and match" but I don't 
recommend it.

If you already have one of the crossover flywheels, then you can just continue 
to use it and your 6V starter on 12V. Just don't go cranking it too long at a 

If your notch has the 6V/180mm flywheel, then you really should change to the 
later 12V/200mm flywheel and the late matching crank. There are lots of reasons 
why this is preferred.

The crossover flywheels are quite hard to find.
Jim Adney

I have done many of the 6V -12V conversions. I just leave the 6V
flywheel and starter. The flywheel will last about 5-10 years with the
using 12V. I have never had a starter fail under these conditions. the
engine starts so fast, it is not engaged very long. 
If you try doing the change to 12V flywheel, you will have to machine
the bell housing. The 130 tooth flywheel is bigger in diameter. If you
go this route, use and automatic starter. They do not need the bushing
in the bellhousing.
There are 2 different crankshafts for the 1500-1600cc engines. the
difference is how the flywheel mounts. The step on the end of the crank
is deeper for the 12V flywheels. A 6V flywheel will work on a 12V crank,
but a 12V flywheel wont work without some machining on a 6V crank.

-- Russ Wolfe
DaveS=> as I redo this Notch in 12 V then I guess I have  to change
=> some other items like the fuel tank sending unit, the fuel  gauge,
=> the clock, lights, relays  etc. Are there other items that I  need to
=> replace that I've missed here?

Been a while since I've listed these, so I hope I don't miss anything:

First -- *not* the fuel sender. Voltage doesn't matter there.

Every bulb: Headlights, front, side & rear markers, tails, signals, 
brakes, reverse if you've got it, cabin, rear compartment, instruments.

Relays: Headlight, horn, flasher

Instruments: Fuel guage (internal module only), clock, radio & speaker; 
if you have a tach, hope it's a multi-voltage model (check for extra 
spades on the back).

Switches: Headlight (because of the dimmer), wiper; if it's a pushbutton 
dash, you'll need the adapter plate.


Wiper motor

Voltage regulator


You have options: Get a Porsche 12V generator (same diameter, high 
bucks), rewind your 6V for 12V, or use a later Type 3 12V and fan housing.


Choke heaters


If you're super-anal, you'll want to change the fuse box as well to 
match your new diagram and gain a couple fuse points. I did, and 
nothing's wasted in there.

I think that's all of it, but chime in if you know more.

Steven Ayres, Prescott AZ
'66 Big Ghia (12V)
Now that you've converted your 6v system to 12v you may have some 6v electrical items
that you need to retain but you can't feed them 12v, so what are you going to do?!  Use a 
drop-down voltage regulator!

From the Ford Truck Enthusiasts website is a "how to" for taking your 12v charging system and dropping
the voltage down to 6v for those gauges and/or other electrical accessories that you need to keep:
12v to 6v voltage regulator.htm

VDO tachometer wiring instructions, page 1  page 2