6 Volt or 12 volt

[qjhart]

6 Volt to 12 Volt Conversion

At some point in the past, this car was converted to a 12V battery up it retained a regulator/generator setup. The information below documents the changes that I think happened in that conversion.

Ignition System

In the following figure (Fig 2). The original coil that came with the jeep (when we got it in 2015) had this additional ballast resistor included in the system. The Ballast resistor resistance goes up as the temperature increases, and allows a higher voltage to start a cold car.

However, the coil we replaced this with (Issue #6) Kaiser Willys #933160 Replacement Ignition Coil 12 volt, has an internal resistor, and so is wired as in Fig 1.

The distributor, ignition points, condenser, spark plugs and ignition wires do not have to be changed when converting to 12 volts.

Charging System

This jeepster has a 12 volt regulator in it. First, some information on the labeling of the regulator and generator terminals. This applies to both the 6 and 12 volt parts. The regulator has a "B", an "A", a "F" and aground terminal. The generator has an "A", a "F"and a ground terminal. These terminals may have slightly different names. "B" may be called "BAT" , "A" maybe called "G" or "GEN" and "F" may becalled "FLD". The ground terminal on the generator is usually a tapped hole that is adjacent to the other two terminals.

In our jeepster, we have this strange 12 regulator. The locations for the wiring is shown

Here is how the wiring should be

The wires connecting to the 6 volt regulator and generator will be as shown in figure 3. The positions of the terminals on the regulator and generator will most likely be different than I have shown in the drawing, so don't try to identify the terminals by their physical positions. If your 6 volt regulator or generator has any extra wires or components connected to its terminals, make sure these wires get reconnected to the proper terminals. The extra component you will encounter most often is an ignition condenser attached to the generator. The body of the condenser will be attached to the ground terminal ofthe generator and the condenser's wire will be attached to the A terminal of the generator. The condenser may have been installed afterthe Jeep left the factory to reduce the amount of static heard in an AM(medium wave broadcast) radio.

Additional Notes.

*Conversion Instructions Probably the most detailed instructions. This is pretty interesting, discussing using a headlight to test the system. This also discusses difference between 12 volt alternator and generator.

• Conversion Instructions, is quite good as well, maybe better for the diagram. Also, interesting stuff like how the ignition switch should be changed to allow the ignition resistor to be bypassed on startup.
• 6 volt vs. 12 volt. Kinda interesting because of discussions on 8 volt, electronic ignition, etc.

[qjhart]

I'm starting to think that it has been converted to 12-volt. This is because of a few things.

• I found some writing on the generator, (which is not new), that says it's a 15 volt generator.
• There is an ignition resistor, (aka ballast resistor), in the wiring for the ignition coil. This seems to be the proof, as descriptions indicate they are needed for 12v batteries and 6 volt coils. Apparently, they weren't required for 6-volt cars.

Another interesting thing there, is they say that the ignition switch should jump that resistor, so that you get more juice when starting. Need to check that as well.

The ballast reduces the current flow thru the coil at low speeds and keeps the coil from overheating. As was said the coil can handle more amperage but not for long periods of time. So at idle and low eng speeds the points have more time to be closed and thus the current heats the ballast up and causes it to have more resistance and drop current flow at lower eng speeds when full coil output is not needed. When you go faster and speed the eng up the points have less time to be closed so the ballast cools down some and the resistance drops causes more current to flow thru the coil and letting the coil output higher when it is needed at higher eng speeds. And when cranking the ign system needs full output to help start the eng so the ign switch bypases the ballast and gives full battery volts to the coil while cranking.

• There seem to be some resistors added later, that go to the heater, and maybe the gauges, (must check), that indicate that as well.

[qjhart]

Determined that it's indeed a 12-volt. Best clue was the ballest resistor on the block.