positive or negative system

[Larry Cecil]

How to you tell which one you have on your tractor. I have a Oliver super 55 the year is 1955 diesel. They ask me this question when I was ordering new battery cables for it. Any help with this would be greatly appreciated.

 

[IanC]

Does it still have the Delco generator, or has it been converted to an alternator? If it is an alternator it will most likely be negative ground (you can get 10SI alternators in positive ground, but they are NOT common and are much more expensive than the "regular" ones). If it is a Delco generator it can be positive or negative ground depending how it is polarized. My 77 diesel is 12V positive ground, the ones on later IH like 706 usage were 12V negative ground.

 

[rvirgil_KS]

If it has a battery in it now how is it connected?

If no battery in it, look at the cables. Positive battery post is larger than negative post. Look at the cable coming from tractor frame, is it the larger or smaller diameter hole in the connector clamp?

 

[gary66]

positive ground is the + side of the battery connected to the frame..follow the wire, if it goes to some hunk of metal and not and electrical component it's positive ground...it is just what it says it is. I think it was a mistake and they just went with it

kind of similar to wiring an outlet in your home backwards, except in a home things work...till you grab what you think is a neutral while touching a copper pipe with your ear lol

 

[rustred]

just look which cable goes to ground. got a 50/50 chance of being right. its either pos. or neg. dont even know why they would ask that unless there is two diff. lengths of cables. plus they should know that info also. lots of times they will ask for the serial # and that tells them what they want to know.i make all my cables .

 

[Larry Cecil]

Thanks to everyone. I am restoring the Super 55 and it has no battery in it now, but has a alternator thinking it is a negative system. Will order new cables from KORVES today. Thanks for your help.