Check out the picture of a regulator in my tech tips article. The far left part, as you're looking at the regulator assembly with the top off is the cutout relay. It's there to prevent the battery from discharging itself through the generator when the engine is stopped. If it's getting a heavy discharge when you touch the battery wire to the regulator terminal, it's almost certainly got a set of stuck cutout relay points. It's nearly impossible to clean up those points where they won't continue to stick, so you'll probably need to replace the regulator, no matter how new it looks. TEMPORARILY, you might be able to clean up the points with very fine sandpaper, like 400 grit or so, but don't get complacent and think it's a permanent fix. One episode of a stuck cutout relay that you don't notice right away will fry your generator, and might result in a fire that destroys the vehicle!
If you can get the cutout relay points clean enough to work without sticking, disconnect all the wires from the generator and put a voltmeter between the Armature terminal of the generator and ground. Start the engine. Slowly increase the engine RPM while watching the voltage output at the armature terminal. it should top out at about 2 volts. If there's no voltage, momentarily attach a battery hot wire to the Armature terminal, for about one second or so. There will be a pretty big spark, so don't panic! Recheck the voltage while the engine is running. If it's there (2 Volts of so), connect the wires and proceed with your diagnosis. if not, remove the generator and get it checked out and rebuilt.
Confused yet? Check out the generator as I've described above, and post your results.
Jerry
