Re: Question About my Generator...

Posted by Ross On 2012/3/7 7:17:50

Would actually expect to see about 7.2-7.4 volts with the engine running at 1500 or so.

You can try polarizing, you only have to jump from battery to armature for a fraction of a second. If your car is hooked up as originally, that is positive ground, that means battery negative post to the armature post on the generator.

I am guessing that the commutator on your generator has oxidized from sitting and won't conduct. You can clean it up with a bit of scotchbrite.


Easiest generator test in the world is this: Remove the fanbelt and wires from the generator. Ground the field winding to any convenient point on the engine with a small jumper lead. Jump battery power down to the armature terminal. The generator should happily and evenly run as an electric motor drawing oh, eight amps or so. If it doesn't run, runs lumpy, or draws a lot of current it will need some loving.

You can also do this test on the bench with a battery charger, just be sure to ground both the case and the field terminal (positive) and apply neg to the armature post.

I test this way before putting any generator back in. It pre-polarizes. If I have put new brushes in, I let the thing run over lunch time to seat the brushes.