"Hybrid" electrical system?

ncoonen

New User
My new-to-me '49 8N (226847) has a strange electrical system configuration. The PO only had the tractor for a year and sold it because his wife wouldn't drive it (to mow a few acres of weeds). He told me it needed a new battery and didn't know if it was 12V or not. It was obvious that it had a 12V battery but...

Today I did a little more digging and found that yes, it has a 12V battery but seems to have the original generator and voltage regulator. This would explain dead batteries. I charged and tested the battery and it seems to be okay. The generator puts out 6-7 volts and the regulator looks original. Assuming someone put a 12V coil in the front mount distributor, would the tractor run with a 6V charging system? Would it run if the coil wasn't changed to a 12V unit?

I've included a couple of back of dash pictures for what they are worth. Someone has replaced at least some of the wiring over the years but a few wires look original with original looking ends. Like those on the regulator. I'd like to keep the original look and would even consider using a 12V generator and regulator if that's what is needed. The PO replaced the starter with a universal 8N11001R because the drive broke off the old starter on a really cold day.

To be honest, the tractor runs pretty well now but I am oretty sure that the battery isn't being charged properly. Old tractors, like old cars can be like an archaeological project trying to peel back the "upgrades" and hacks to make it work.

Thanks for your thoughts...ned.



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They probably just stuck a 12v battery in there & sold it. Ignition uses such a small current that unless one uses the starter a lot, they will run a long time on a charged battery, as in several tanks of gasoline. Does look to be original regulator. You should be seeing ammeter movement. Since they probably have the 12v battery negative post tied to tractor ground, it may be showing a charge current that is actually a discharge current since battery ground originally as Positive to tractor frame/engine ground. Meter movement will just barely be perceptible as running ign current only averages about 2 amperes, which isn't much movement on a 30 ampere meter.
 
Good point. I forgot to mention that the battery is wired with a negative ground. The ammeter does seem to show charge when the engine is revved a bit over idle. It's easy enough to flash the generator and change its polarity. That may have happened accidentally.

(quoted from post at 14:35:00 01/29/18) They probably just stuck a 12v battery in there & sold it. Ignition uses such a small current that unless one uses the starter a lot, they will run a long time on a charged battery, as in several tanks of gasoline. Does look to be original regulator. You should be seeing ammeter movement. Since they probably have the 12v battery negative post tied to tractor ground, it may be showing a charge current that is actually a discharge current since battery ground originally as Positive to tractor frame/engine ground. Meter movement will just barely be perceptible as running ign current only averages about 2 amperes, which isn't much movement on a 30 ampere meter.
 
(quoted from post at 17:47:59 01/29/18) Good point. I forgot to mention that the battery is wired with a negative ground. The ammeter does seem to show charge when the engine is revved a bit over idle. It's easy enough to flash the generator and change its polarity. That may have happened accidentally.

(quoted from post at 14:35:00 01/29/18) They probably just stuck a 12v battery in there & sold it. Ignition uses such a small current that unless one uses the starter a lot, they will run a long time on a charged battery, as in several tanks of gasoline. Does look to be original regulator. You should be seeing ammeter movement. Since they probably have the 12v battery negative post tied to tractor ground, it may be showing a charge current that is actually a discharge current since battery ground originally as Positive to tractor frame/engine ground. Meter movement will just barely be perceptible as running ign current only averages about 2 amperes, which isn't much movement on a 30 ampere meter.
/quote]

Polarizing the generator won't change the reverse ammeter deflection.

TOH
 

to fix the direction the ammeter needle moves, u need to reverse the direction that wire runs thru the ammeter loops.
 

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