Posted by Paul Cook on Thursday, October 20, 2005 at 5:55PM :
In Reply to: Can't jump start anybody with a 6v system nm posted by chriscase on Thursday, October 20, 2005 at 2:20PM :
Hmmmm! Does that mean one cannot jump start a vehicle that has a 6v system using a vehicle with a 12v system? - or - Does that mean one cannot jump start a vehicle that has a 12v system using a vehicle with a 6v system.
There is only one way to jump start a 6v vehicle using a 12v vehicle in a manner that will not cause damage to any electrical components of the 6v system. Click on the Museum link below, then scroll down the Museum front page to the Technical Support Section and click JUMP 6 w/12. It takes two people!
It is possible to jump start a 12v vehicle using a 6v vehicle that has a large capacity battery with a maximum charge if the 12v vehicle engine is in good tune and warm - the same conditions that would make it easy to start it with a hand crank. I've seen this done back in the days when both 6v and 12v vehicles were common and before alternators and solid state electrical components were around. You'd have to use the same procedures as in the JUMP 6v w/ 12v mentioned above. Again, it takes two people.
The only way one person can jump one vehicle with another that is reasonably safe for the electrical systems of both vehicles is when they are both of the same voltage. You can jump vehicles of different ground polarity if they are electrically isolated - NOT TOUCHING.