Red 460 7 Posted November 28, 2016 can anyone tell me if a 335 cummins is 12 or 24 volt system and if so I do I tell the difference thanks Share this post Link to post Share on other sites
j hancock 10,338 Posted November 28, 2016 The starter may still have a tag indicating what it is. With old equipment, it can be interesting to determine because what may have been done to the vehicle by previous "mechanics". If the battery jumper cable goes from pos to neg you will get 24 volts out of two twelve volt batteries. If two or more 12 volt batteries have the jumper wire going pos to pos or neg to neg, than you still have 12 volt but much more capacity. Share this post Link to post Share on other sites
Red 460 7 Posted November 29, 2016 Thanks for the reply I haven't got that far in it I just saw 2 battery and all4 cables head to the starter and wondered why Share this post Link to post Share on other sites