jumping with 12V
 

Hey guys,

I don't normally post over here but i have a question:

A buddy of mine has a '56? and he tried to jump start it a couple of months ago with a 12V system.

He says that it is a 6V system in the truck but he was told that you can jump with 12V if your really quick about pulling the cables.
sounds suspect.

He says that when he tried to jump the truck he heard a loud POP and now the truck won't start.

I haven't actually popped the hood and looked for myself yet but what do you guys think?

Re: jumping with 12V
 

A 56 pickup should be 12 volt

Re: jumping with 12V
 

I'm not sure what year GMC went to 12 V but they were positive ground until 59. If its a chevy then 56 should have been a 12v already.

Does it not crank or not run?.

Re: jumping with 12V
 

Won't turn over or turns over and will not start? years ago I haD a 6v flathead Ford that occasionaly needed to be boosted and all my friends had 12 v rigs. never hurt the charging or starting system jumping it, but it was a generator. If the 56 is stock it should be a generator too.

Re: jumping with 12V
 

If you go + to + and - to - you should be good even if the ground polarity is different.

I'm pretty well positive that that truck should be 12 volt though.

On question, why does he believe that the truck is six volt?

Re: jumping with 12V
 

56 should be a 12v system only thing that would cause a pop is the cables hooked up backwards

Re: jumping with 12V
 

i could be incorrect about the year. what year did gm go to 12v?

Re: jumping with 12V
 

I've been hunting for info and haven't found anything specific as to which year the change was. I thought it was with the change of body styles but that may not be so.

Re: jumping with 12V
 

chevy 55. gmc 56