6-Volt or 12-Volt

6 Volt or 12 Volt?

Dodge changed from a 6 Volt positive ground electrical system to a 12 Volt negative ground electrical system sometime during 1955 or 1956. Before the changeover all WDX through C-3 Power-Wagons were 6 Volt, and after that point all C-3 through WM300 Power-Wagons were 12 Volt.

Looking through the Factory Parts Books, Service Manuals, and Service Bulletins, it looks like the change from 6 Volt to 12 Volt was made at serial number 83949001.

Unfortunately, the production records for this era have been lost, and putting a date of manufacture on a given serial number can not be done. Because of this it is not clear if Serial Number 83949001 was in 1955 or 1956. The best guess is the change was made early in calendar year 1956, or mid year in the 1956 model year. The earliest literature found so far to mention 12 Volt parts was dated February 8th 1956.

Here are a few clues to tell if a truck was 6 Volt or 12 Volt from the factory.

The 6 Volt trucks have red tags that say 6 Volt on the Generator and Starter motor, 12 Volt trucks have green tags that say 12 Volt. Below are a couple pictures of the Generator and Starter motor 6 Volt tags on a 1955 C-3 PW.

Generator 6 Volt	Starter motor 6 Volt
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Here is a 12 Volt tag from a Generator, all the 12 Volt tags are in the same locations as the 6 Volt tags.

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Dodge changed the AMPS gauge when the trucks went from 6 Volt to 12 Volt and this change can be used to determine if your truck was 6 or 12 Volt. Starting in 1951 Dodge changed to a different set of gauges, and moved the gauge cluster in the middle of the dash. The AMPS gauge in this new gauge cluster had different markings for a 6 Volt truck vs a 12 Volt truck. From 1951 up until 1955 or 1956 when 12 Volt was introduced Dodge used an AMPS gauge that read 50 - 0 + 50 on the 6 Volt trucks.

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Starting with the 1955 or 1956 Power-Wagon, Dodge went to an AMPS gauge that read
30 - 0 + 30 for all the 12 Volt trucks, this gauge was used until mid year 1966. Sometime in mid 1966 Dodge went to an ALT gauge that read D 0 C.

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Another thing that changed when Dodge went from 6 Volt to 12 Volt were the dash knobs. The 1955 or 56 6 Volt trucks got chrome metal knobs with black inserts, and the 1955 or 56 12 Volt trucks got black plastic knobs.
Note: The picture on the left below is of a dash from a 1955 C3-PW6-126 with 6 Volt knobs and the picture on the right below is of a dash from a 1956 C4-PW6-126 with 12 Volt knobs.

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I hope to update this page from time to time as more info becomes available, and feedback is given about other information that would be good to include on this page.

Please contact the Registry maintainers at the below email address if you have any suggestions or questions.