Generator trouble shooting?

[tommy]

57 Ford, 12V neg. ground. Gen. Light came on at night with the H/Ls on. Pulled the gen. Nice full brushes. Polished the commutator and cleaned the segment slots. Put it back together and the same thing. The light would only dim when revved up to 2500/3000 rpm with only the ignition load. The light never went out. Put in a new V/reg and battery. Same thing. Took the gen. to the gen. shop. They say it charges fine on the bench. Now the light stays on and doesn’t dim. I suspect the brand new V/reg. Yes I polarized the gen. every time something was changed. I even wire brushed the connections and the ground screw on the core support. I spliced an ammeter in the line and it never moved.

Is there an easy way trouble shoot the new V/reg.? Run a jumper from F to B to get full charge? If it’s still good I don’t want to burn it up. Generators are supposed to be easy to fix. Well, this one wants to kick my ass. What simple thing am I missing?

[286merc]

Did you wire brush the VR mounting holes on the sheetmetal and use new shiny screws? Also how are the contacts/wiring at the VR? Bad grounds and poor connectors (held on by a strand or two) can drive you crazy.

If you need genny and VR trouble shooting info I can scan and EMail you some info out of the manual.

[TagMan]

An easy way to check to see if a "no charge" condition is being caused by the generator or voltage regulator is to
remove the Field wire (F) from the voltage regulator and connect it to ground. Increase the engine speed. If the ammeter shows it's charging, the voltage regulator is bad. If the ammeter shows no charge, the generator is bad.

After installing a new volt. reg., be sure you polarize it by placing a wire between the Battery (B) connection and the Armature ("A" or "GEN") on the voltage reg. for just an instant, just enough to "spark" it.