Re: 12 volt Packards?/Negative ground Packards?

Posted by DrewLA On 2014/5/9 2:37:12

The wiring necessary for 6-volt is heavier gauge and as such will carry the current necessary for 12-volt loads just fine. There is no difference between the 6 and the 12 volt wiring schematic other than that smaller gauge (higher number) wires could be used and that a ballast resistor will need to be added at the distributor. Apart from that, there is only one actual change to the schematic -- which terminal of the battery is grounded. Flip it around so the negative side is grounded, and you should be good to go.

This, of course, assumes that you have converted everything that's either polarity sensitive or voltage sensitive (no small feat).

12-volt conversions are one of the biggest points of argument among folks in the classic car hobby. Many of us, myself included, take the stand that 6-volt is more than sufficient and that 12-volt conversions are most often undertaken to mask a problem rather than fix it. That is, unless you want to add A/C, in which case more current is usually necessary than a 6-volt generator can supply. There are ways around that, for instance by changing to a 6-volt alternator and then adding a step-up transformer to put 12-volts only where those accessories require it.

But, assuming you want to convert to 12-volt, follow the factory wiring diagram and either convert the loads or put voltage reducers before each one.

Voltage sensitive loads:
-Light bulbs (change each bulb to the corresponding 12-volt equivalent, WAGNER has a cool chart)
-Horns (horns are a very high amp draw, suggest replacing)
-Radio
-Antenna (if electrically operated)
-Starter (have it checked, may or may not be necessary)
-Heater blower motor
-Ignition system (use a ballast resistor to drop the voltage to 6v)
-Gauges (51-54 gauges operate at an average voltage of 5v; Ford used a similar setup until the 1990's, so there are several Ford gauge voltage regulators made for their 12v cars which would work to drop the voltage to the 5v the gauges like to see)

Polarity-sensitive loads:
-Heater blower motor
-Radio (if a solid state vibrator is installed)