Posted by David Sheman on Thursday, April 29, 2004 at 11:57AM :
In Reply to: How do I figure which terminal is on the 24V Gen posted by Willy-N on Thursday, April 29, 2004 at 0:27AM :
I would try to take it apart and look physically to see where the wires go. That would give you a chance to check the brushes while you're at it, clean up the commutator if need be, and see how the bearings are. The ground pin would of course go to the case, the "gen" pin goes to one of the brushes, and the "field" pin goes to the field which is attached to the frame. If you can't follow the wires, take out the rotor or one of the brushes and see which pin "opens up" to ground. That's the "gen" pin. Of the 2 that are left, the one with the highest resistance to groud (probably couple of ohms) is the field. If I didn't want to take it apart, I would just bolt it to the engine, get it turning, and then try applying a little current to each of the pins successively, though a limiting resistor, like maybe an ignition resistor. Each time you put current into one pin, check the voltage on the other pins. When you find one that has lots of voltage on it, when current is applied some other pin, you've got it figured out -- the one the current is going into is the field, the one the strong voltage is on is the gen pin and the other one is the ground. The good thing with an old-fashioned generator is you are unlikely to hurt anything by briefly hooking it up wrong, especially since you'll be standing there to see (or smell) if anything sparks too much or gets hot. All that said, I will look in the TM when I get to my office today and see if it shows the pin-out of the generator connector.