electrical issues

Jon Zander

New User
Im new to this stuff. Im a young guy and nobody has been around to teach me about this kind of stuff. I recently bought a 444 massey harris because it has sentimental value to me. I love to learn about this stuff. I plan to restore this tractor. Well i bought it thinking it would only need a carb kit and be good to run... well, the battery died after the haul, so i took it off and charged it red->red and black->black. (This is a 12v positive ground just so you know. The owner before me converted it to an alternator). After i got the battery charged up and ready to go i put it back on how i found it, red to the frame and black to the solenoid. And immediately when i put it on, the ground wire to the alternator started smoking and melted the insulation off around that wire. So i took the battery off and tried again. Sure enough it started smoking again. And it wouldnt even crank. Where did i go wrong?
 
Unless specially modified an alternator must be configured as a negative ground system.

The tractor probably came from the factory positive ground with generator, but sounds like when the previous owner installed the alternator he did not change the battery cable colors.

Connecting the alternator with positive ground let the smoke out of some internal components.

Replace alternator, replace battery cables and check charge wire from solenoid to amp gauge (if it has one) and to alternator.

To avoid future confusion I'd mark the battery cables for + and -

Also with negative ground the - post on coil goes to distributor.

Other possibility is that this may be a modified positive ground alternator and there is a short to frame on cable going to solenoid.
 
99% of alternator system use a - ground so when you hooked it up + ground you let the smoke out of the alternator so now you need to recharge the battery and replace the burned wires and buy a new alternator. Only takes a split second and you fry them by hooking them up the wrong way. By the way wire color means nothing when it comes to old stuff and what some one else has done. Always check where the battery cable goes before hooking a battery up
 
Was it hooked up positive ground, or did you assume that?

I agree with the others, 99% of alternators are negative ground.
 

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