Oliver 550 electrical question

[Ollie03031]

The other day mowing with my 550 I broke off the field wire to the generator. I did not notice it for
many hours but the tractor ran fine. When the sun was not as bright I noticed the Amp light on, thats
what got me checking the wires. Replaced the wire to the Field terminal but the Amp light has stayed
on. This is the original positive ground 12 volt system. Been investigating the issue and found the
generator was only producing about 3 volts between the F and A terminals. Started thinking I need a
generator rebuild until I read in the Oliver Maintenance Manual about polarizing the generator. That
claims when the two wires have been removed the generator may need to be polarized. If thats correct
breaking that wire and operating for a few hours with it broken and then fixing the wire without
repolarizing the generator would that do damage to the generator. Should I try polarizing the generator
as it describes in the manual?
Second Question? The above tractor is a 1965 I also have a 1964 Oliver 550 Special which is wired
completely different. Someone changed it to a negative ground and a 12 volt battery. (Note I thought
all 550 were 12 volt.). The Special the generator creates 7 volts and the voltage regular is regulating to
6 volts even though it has a 12 volt battery. I hardly ever use the Special but am confused should this
have a 6 volt battery?
Thanks
Ollie

 

[oliver90owner]

Re-polarising costs nothing. I know which I would try first!

How is running it, without it charging, going to damage it?

Your second question does not make sense. A 6 volt generator will never charge a 12 volt battery. I think you are muddled, somewhere.

Polarity is a different matter entirely, usually most important only if the early dynamo generator was replaced with an alternator generator. Alternators were never produced as 6 volt units (as far as I know).

 

[Ollie03031]

I did a polarization and it did not change anything. The voltage across the A and F terminals reads 2.7 volts. I believe my next step is getting the generator rebuilt.
Yes my 550 special is confusing. I have never had an issue with it starting but I seldom use that tractor. I wanted to compare measurements between tractors to
find the problem an I first found out the someone had changed it from positive to negative ground. Then I found the generator generated around 7 volts between
the A and F terminals. Next I found the regulator was regulating at around 6.5 volts but it has a 12 volt battery. I have reached out to the original owner to try to
determine what they did but have not heard back. Also I saw that possibly some early serial numbered 550 might have been 6 volt but not sure. This is a 64 while
the one with the problem is a 65. Both have been totally restored.
Both seem to have the original generators and voltage regulators but the 64 was changed to a negative ground.
Thanks
Ollie

 

[J. Schwiebert]

All 550 tractors were 12 volt. 12 volt started in January of 1957 with the Super 55 models. Send me an e-mail. Include your phone number. J.

 

[Ollie03031]

I am having the generator rebuilt on the 65-550. It tested bad. May need a new regulator also but will not know until I get the generator back.
J. On the 64-550 Special I a still confused. I read that all 550 were 12 volt positive ground as you stated. So I was surprised when I was reading 6 volts out from the regulator and 7 from the generator. Also was surprised when I found it was converted to a negative ground. I still need to recheck my measurements. It will be a few days before I get back to the farm where I keep and use the tractors. I only trailer them to my house when preparing to take them to a show or parade.

 

[Ollie03031]

Rebuilt the generator and it running again and the amp light is off.
Thanks