Hey, I'm stumped. I rescued a 1950's vintage Hobart GW222 DC welder generator powered by a 2 cyl Wisconsin motor. It sat for decades unused in a barnyard, out in the weather. The generator was full of pack-rat crap and the rats had chewed all the insulation off the wires. I pulled the stator off and cleaned everything, checked all the coils, and re-insulated them. Everything checks out for continuity. I refurbished the armature and checked for broken/grounded windings. I don't have a growler, so I just checked with a multimeter, both a 180 commutator check, a side-by-side commutator check, and a grounding check between the commutator and the armature irons stack. There don't seem to be any broken or grounded windings.
This is a compound DC generator with both field coils and shunt coils.
The engine runs great.
I put everything back together, wired up according to the wiring schematic, and tried to energize by hooking a 12v car battery to the pos and neg brushes. Nothing. I got s little spark glimmer under the positive brush that I had the battery hooked to, but that's it. I tried energizing the shunt circuit by hooking the battery wires to opposite ends of the shunt circuit. Nothing. I tried the same thing with the field circuit. Nothing. This thing won't make any current.
I double checked the armature to make sure the windings were good. Best I can tell, they are.
I have had good luck re-energizing old Pipeliners by hoking the 12 v battery to the exciter generator. But I'm a bit lost on this old Hobart. It's simpler in some ways than the Pipeliner, but it has separate single shunt and field coils mounted on top of the generator yoke, instead of in the stator ring like a pipeliner. I wonder if maybe I just need to hook the battery up to it and leave it there for a while. Either the thing is so dead it can't magnetize, or something is broken or grounding out.
Any thoughts tricks or suggestions?
Thanks!