6 Comments on “When did CJ-5s switch to 12 Volt?”

1. Craig B. October 20, 2011 at 1:47 pm

   I’m pretty sure the switch came during the 1957 model year. Many ’57’s came 6 volt but I believe that late in the year they switched over to 12 volt.
2. Bob October 20, 2011 at 3:58 pm

   I believe Craig B is right. I always heard about 1958 but he may be more precise.
3. modmike October 20, 2011 at 5:35 pm

   Yes, I agree that within the 1957 model year the change over was made. I used the Willys America parts list book as a reference.
4. Dave October 20, 2011 at 7:15 pm

   Taking the information from the “Standard Catalog of Jeep 1940-2003” by Patrick Foster—
   “By 1958, 12 volt electrical systems had become standard equipment in Jeep vehicles.”
   As I remember, the 6 volt system was an option for several years after that, but I don’t have any idea when that was dropped from the option list.
5. Ron Damron October 20, 2011 at 9:52 pm

   Dave-

   I restored a 1957 Willys CJ-5 for my brother back in the mid 70’s and it had a 6 volt charging system. If my memory serves the late 57 year CJ’s converted to 12V. My 1956 CJ-5 had a 6V system when I bought it and I converted it to 12V and upgraded to a GM 1 wire alternator. Pain in the butt to wire up seeing as I’m hefty and don’t fit under the dash easy.

   Ron
6. Wayne Dunard October 21, 2011 at 5:44 am

   In 1957 Willys used up all the 6v they had then switched to 12v.