Positive or Negative Ground

[coozman]

So I picked up this 9N, guy told me it was converted to 12 volt. This looks like an old generator (says Ford V8 on it). There is no battery in it to see which post goes to ground. If the generator was reworked, is it a positive ground or negative ground system?

 

[Duner Wi]

Install a battery positive to earth. Turn on headlights. If it shows discharge it is positive ground. If it shows charge , reverse the cables.

 

[coozman]

That would work except there are no headlights on the beast.

 

[TheOldHokie]

So I picked up this 9N, guy told me it was converted to 12 volt. This looks like an old generator (says Ford V8 on it). There is no battery in it to see which post goes to ground. If the generator was reworked, is it a positive ground or negative ground system?

It does not matter if its 6 or 12 volts. If its a generator its whatever polarity you make it when you polarize it.

TOH

 

[MM-TX]

The positive post is larger. Look at your cables to see how it was hooked up last.

 

[Duner Wi]

That would work except there are no headlights on the beast.

With points closed the ammeter will show slight discharge with key on. If ammeter moves to charge when key is turned on, cables are backwards.

 

[TheOldHokie]

With points closed the ammeter will show slight discharge with key on. If ammeter moves to charge when key is turned on, cables are backwards.

Or ammeter is wired backwards Polarize the generator when installing the battery and theres no ambiguity.

TOH

 

[Duner Wi]

Or ammeter is wired backwards Polarize the generator when installing the battery and theres no ambiguity.

TOH

Normally a 12 volt conversion would include wiring ammeter to show discharge with a draw on the battery.

 

[TheOldHokie]

Normally a 12 volt conversion would include wiring ammeter to show discharge with a draw on the battery.

He has a pig in a poke "conversion". - nothing van be trusted including the ammeter connections. Start from scratch by polarizing the generator to a known state.

TOH

 

[Duner Wi]

He has a pig in a poke "conversion". - nothing van be trusted including the ammeter connections. Start from scratch by polarizing the generator to a known state.

TOH

I agree with what you say. I am just addressing the question. Lots of variables here to mull over. I am sticking to the question.

 

[TheOldHokie]

I agree with what you say. I am just addressing the question. Lots of variables here to mull over. I am sticking to the question.

The question was "is it (the generator) positive or negative ground?" The answer is nobody knows - pick the one you want, polarize generator to match, and hook the battery up accordingly.

Barely a year gone and JMOR must be rolling in his grave.

TOH

 

[Duner Wi]

The question was "is it (the generator) positive or negative ground?" The answer is nobody knows - pick the one you want, polarize generator to match, and hook the battery up accordingly.

Barely a year gone and JMOR must be rolling in his grave.

TOH

Now we what the meaning of is is. You are correct. I mistook the question to mean how was the last install. Negative or Positive ground. You are 100 % correct. My wife is excellent in determining what instructions say. I'm in group of what I think the instructions say. This gets me to grief sometimes. I have her read and tell me what actually the instructions are saying.

 

[coozman]

Thanks for the info everyone. Going to jump in tomorrow and see if we have any luck getting her running.