Converting the electrical system of an antique tractor to 12 volts from the original six volts is a good idea for several reasons. Brighter lights, faster starting and cheaper electrical components head the list. An ideal time to do so is when the original six-volt generator has problems, because replacing the generator with a 12-volt automotive alternator costs less than rebuilding the generator. You can reuse the original wiring if it is in good condition, since the new 12-volt components will use less current than their six-volt counterparts. You will also be converting from the original positive-ground system to a more modern negative-ground system.
Things You'll Need
- Delco internally regulated automotive alternator
- Steel bar stock, 1/8-inch by 1-inch
- Drill and bit set
- Wrench set
- 16-gauge insulated wire
- Crimper and terminal set
- Ignition ballast resistor
- 12-volt light bulbs
- 12-volt battery
Remove the old generator and replace it with the 12-volt alternator. If the mounting holes on the alternator don't match the existing bracket, cut and drill a piece of the bar stock to adapt. Remove the original voltage regulator, as you will not be reusing it.
Connect the large-gauge wire from the battery to the "Bat." terminal on the alternator.
Connect a short 16-gauge jumper wire from the "Bat." terminal to the "2" terminal on the alternator.
Locate a connection that is energized when the ignition switch is on. This will be one of the wires that connected to the original voltage regulator. Connect a 16-gauge jumper from this connection to the "1" terminal on the alternator.
Replace all light bulbs with their 12-volt equivalent. Tractor parts stores and auto parts stores can cross-reference these for you.
Disconnect the wire from the "Bat." terminal of the ignition coil. Connect the ballast resistor between the wire and the coil.
Replace the six-volt battery with the new 12-volt battery. Connect the ground cable to the negative post and the nonground cable to the positive post of the battery.
Tips & Warnings
- Double-check your work before connecting the battery.
- Do not crank the starter for more than 10 seconds, as it will become hot more quickly than it did with six volts.
- Photo Credit Vintage Orange Tractor image by Joy Prescott from Fotolia.com
How to Change a Tractor Tire
Tractors are heavy-duty vehicles. Replacing an old worn tire is not an easy task, especially if you have never changed a tire....
How to Wire an Alternator on a Tractor
One of the easiest and best improvements that can be made to an older tractor is to replace the original generator with...
How to Convert 12 Volt to 6 Volt
Most power supplies (such as batteries or wall outlet electricity) must be used in conjunction with a power supply circuit to power...
How to Convert a Ford 8N Tractor From 6 Volts to 12 Volts
Converting a Ford 8N from a 6 volt to 12-volt electrical system may not be as difficult as you might expect. For...
How to Convert a Ford Flathead to 12 Volts
Converting your 6-volt Ford flathead car, truck, or tractor to 12 volts does not require replacing everything associated with the electrical and...
How to Change a Farmall From a 6 Volt to a 12 Volt
Converting your Farmall from 6-volt to 12-volt upgrades the electrical system to the industry standard. By doing so, you make it easier...