Home
How to Convert your 6
volt vehicle to 12 volts by Al at AutoReWire.com
Making the
conversion from 6 volts to 12 volts is pretty straight forward.
I get a lot of emails regarding this subject. What I have done
here is to provide you with a sort of road map to perform the
conversion. Obviously you will need a few parts and some
supplies. I have included links to the products that we normally
keep in stock and have included links to others that supply products we
don't stock.
If your wires
are in good condition they will handle the 12 volts just fine as they
are twice as heavy as they need to be. The same is true of the
switches in the vehicle.
Remove the old Battery and DO NOT
INSTALL THE NEW ONE UNTIL YOUR DONE.
GENERATOR If you are keeping a
generator you will need to replace both the generator and the voltage
regulator with units for a '55 or later 12 volt model.
If you are replacing the generator with an alternator I would suggest
that you Google "replace generator with alternator" for a better
understanding of what is involved. I will outline below the most
popular GM 10/12 SI alternator conversion. I have also supplied
links to Mark Hamilton's site as he does a great job of describing the reason
for using a 3 wire instead of the popular 1 wire alternator.
Other alternators will install similar to the GM. More
information is available on the web via your favorite search engine.
GM 10 or 12 SI ALTERNATOR - Most Popular
Conversion
Remove the generator, voltage regulator and the wiring between the two.
Mount a GM 10si or 12si alternator in place of the generator.
Universal brackets are available at most local Napa auto parts stores. On most
vehicles you can simply cut the appropriate lengths of 3/8" black iron
pipe to make the spacers you need to install and align the alternator. You
may have to change pulleys if you have an older engine that uses a wide
V belt (more info here).
For information on part numbers and case clocking go here.
You will need to open up the wiring harness to do this if you haven't
already. We have 1" Non Adhesive Harness Tape available to
properly re-wrap the harness here.
Splice a 10 gauge wire onto the BAT wire that went to the voltage
regulator and connect it to the BAT terminal on the GM
alternator. Don't go to the trouble of buying a 1 wire alternator
unless you just want to get a chrome unit. The factory 3
wire units will last longer and charge better. For more info on this subject go here.
If you are using an ammeter in the dash DO NOT use an alternator larger
than 63 amps and MAKE SURE that you install a 4 inch (minimum) length
of 16 gauge fusible link between the alternator and the ammeter
so that the gauge does not become the fuse in the circuit. I like
to install the fusible link at the alternator to keep it out of the
passenger compartment and for ease of service if it should ever
fail. We have the Fusible Link Kits available.
If you have a dash indicator light splice a length of 20 or 18 gauge wire between the wire that went to the ARM on the
voltage regulator and connect it to the # 1 terminal on the
alternator. Go here for a drawing. If you DO
NOT have a dash indicator light you will need to run a 20 or 18
gauge wire from the IGN switch to the # 1 terminal on the alternator
and install a 10 Ohm 10 Watt resistor somewhere in that line in a place
where it has good air circulation. Failure to install this wire
with the proper resistance will usually burn up the voltage regulator
in the alternator.
It is best to run at least 36 inches of 12 gauge wire from the #2
terminal on the alternator to the BAT connector on the starter solenoid
(or the fuse panel or the horn relay) as apposed to just jumping it as
shown in my drawing. If you read the Mark Hamilton article you
will know why.
Another tip on Fusible Links. GM
designed the systems with the sensing splice in the harness and the 10
gauge system supply wire has a fusible link at the starter
solenoid. If you run the sensing wire to the starter solenoid you
are smart to install a fusible link in it AND in the BAT charge
wire. The ROT (rule of thumb) is to
use a fusible link that is four sizes smaller than the wire you are
protecting. So if you using a 10 gauge wire from the alternator
to the starter solenoid then you would use a 4 to 6 inch length of 16
gauge fusible link. 12 gauge wire will need an 18 gauge fusible
link.
OTHER PARTS
STARTER... Your existing 6 volt starter will work just fine for a
long time if you do not crank it for long periods of time. Of
course cranking any starter for long periods will burn 'em up (as in throwing solder due to over
heating) but the 12 volt driven 6 volt starter will get hot quicker and
throw solder sooner that a 12 volt unit Replace the starter
solenoid with a 12 volt unit for a '55 or later model. We have
the early Ford style in stock.
COIL... You can use the original coil but you must install a new
ballast resistor (1.2 to 1.8 Ohms) between the coil and the ignition
switch. I always test the coil output when I convert a car for a
customer but it requires a special tester that most people don't
have. Anything over 30,000 volts is sufficient for a non
performance engine. You will need to reverse the polarity of the
coil if your 6 volt systems was Positive
ground as most were. Wiring should run from IGN switch to one end
of the ceramic resistor then from the other end of the resistor to the
+ post on the coil then from - post on coil to the points.
Points and condenser can be retained if they are in good
condition. If you need a new condenser, one for any 12 volt
vehicle '55 or later that fits in the distributor will work.
HORN RELAY... Replace the horn relay with a 12 volt unit.
Most 6 volt horns will work for a very long time on 12 volts,
eventually you might need to change them to 12 volt units. Most
fan fair horns and some trumpet horns have an adjustment knob on the
disc that you can adjust the tone with. I wear ear protection
when doing this, you should too. We have some good USA
manufactured units available. Just give us a call or email... They are
plentiful at the local pull your own part wrecking yards too.
LIGHTS... Replace the headlamps and all of the light bulbs with new 12
volt units. Yes this means you have to replace the ones in the
dash that are sometimes very difficult to get to. Resistors and voltage
reducers will not work properly DON'T BOTHER TRYING.
GAUGES... Install one of our $3.00 (each) voltage
reducers for each of your electrical dash gauges. Not needed
for the Ammeter.
HEATER ... Install a 1 Ohm ceramic
reducer between the heater switch and the heater blower motor.
WIPERS... If you have electric wipers you will need to install a 1.5
Ohm ceramic
reducer between the switch and the motor. The 1.5 Ohm
resistor works best on the small wiper motors but we have found that
some of the larger motors prefer the 1 Ohm. If you are not sure I
suggest that you purchase a 1 Ohm for the heater blower motor and try
it on your wiper motor before you purchase the 1.5 ohm resistor.
With the motor running on the high speed you want to see somewhere
between 6 and 7 volts at the motor. If the motor is running too
fast for your liking then I would suggest that you use the 1.5 ohm
resistor.
TURN SIGNALS... Change turn signal flasher to a 12 volt
unit. We have several different types in stock.
POWER SEAT and CONVERTIBLE TOP MOTORS... Most will work fine with
a 1 Ohm Ceramic Resistor others will need a pair of 1.5 Ohm Ceramic
Resistors wired parallel to produce .75 Ohms. Best way to test
for what you need its to install a 1 Ohm
and then check the voltage at the motor with it running. It
should be between 6.5 - 7.5 volts although something less will work
without damage. If the voltage is below 6 volts you might need to
go to two 1.5 ohm resistors wired parallel.
RADIO... As for the radio, the best bet is to go to Custom Auto
Sound and get a unit that will replace your original.
You could also have your 6 volt radio rebuilt to work on 12
volts. Do a Google search on "Antique Auto Radio" for more
information. For the D.I.Y. (do it yourselfer) who wants to "try"
and make your original radio work on 12 volts read this and this.
CLOCK... It is best to have a new quartz movement
installed. Do a Google Search on "Automotive
Clock Quartz Conversion" for more info.
To purchase any of the above products please visit our Web Store or our Ebay
Store. If you can't find them in our stores we are
temporarily out of stock. You can call me at 209-481-6496 anytime
8am to 8pm Pacific time to order with a
credit card or send me an email with
your needs and I can send you a Paypal
invoice. International shipping is available.
Any and all comments are
welcome. If you feel something should be added please let me
know. Al@AutoReWire.com.
Al
eMail=Al@AutoReWire.com
Home