Hooking Up the Battery on a Modified 1951 8N

[ohmsteader]

Greetings!

I made a dumb mistake when I replaced the battery on my 1951 Ford 8N: I didn't write down which side the pos and neg terminals were on. I'm 90% sure I remember which side was negative, but I want to make sure before I hook up the new battery.

The previous owner installed a 12 volt battery, so the original electrical system has been modified.

I assume that because there's a 12 volt battery installed, the system is negative ground. Is this a safe assumption?

I see the cable running from the battery that runs directly to the tractor chassis. --> that's the negative lead, if my assumption above is correct.

If so, then the other cable running from the battery which runs to the generator must be the positive lead.

Please let me know if I'm on the right track.

Thank you,

buzz

 

[pmsmechanic]

You should be able to tell by the size of the cable ends. The negative post is a bit smaller than the positive one.

 

[ohmsteader]

Well, yes, except I removed the cable ends, because the old battery had a different style of connection.

I don't know what to call it, because I haven't seen that type of terminal connection before or since.

So, I bought new cable ends, since the new battery has the standard terminal posts with which I'm familiar.

 

[blacklion66]

Negative is the ground ☺☺

 

[ohmsteader]

So, you're confirming my assumption that this is a negative ground system now?

 

[LD1]

Tractors were originally 6v POSITIVE ground with 6v generator.

12v conversions usually included an alternator.

Does yours have alternator or generator

 

[ohmsteader]

I think it's an alternator, but I'm not sure. Is there a surefire way to tell?

 

[ruffdog]

Which side of the coil (+ or -) is the points connected to?

 

[ruffdog]

On a neg ground system, neg side of coil goes to points. On a pos ground system, the pos side of coil goes to points.

6volt positive ground question? - Technical - Antique Automobile Club of America - Discussion Forums

 

[kuschneider]

Do not assume that is (-) ground just because it has a 12v battery.