I have outlined the test sequence for diagnosing a generator/regulator type charging system several times, so there should be plenty of information available in the archives. Here goes, one more time!
Step 1:
Disconnect the Armature and Field wires at the generator. Start the engine and run it at a speed somewhat above idle. Connect a voltmeter between the ARM. terminal and the generator housing. You should find somewhere between 1/2 and 3/4 volts DC present at the ARM terminal. This is called "residual voltage". It comes from a slight amount of magnetism retained in the armature core. If not, polarize the generator again by connecting a jumper lead from battery voltage to the ARM post momentarily. Engine running or stopped doesn't matter for this procedure.
Step 2:
Reconnect the wires at the generator. Monitor voltage at the ARM wire either at the generator or the regulator, and connect a jumper wire from the F terminal of the regulator to ground. The voltage at the ARM terminal should rise without limit as the engine speed is increased. Do not allow it to go above 15-16 volts. If the above tests are good, your generator is OK.
Check the voltage at the voltage at the BAT terminal of the regulator with the engine at fast idle. If it is not within a couple of tenths of a volt of the ARM terminal, you have a bad regulator, dirty regulator points, or one that's out of adjustment. Battery terminal voltage with a good condition charging system should be in the range of 13-14.5 volts, depending on the state of charge of the battery. Voltage below 13 indicates problems. Voltage below 12.6 or so indicates a "no charge" condition.
Now, if things go as usual, people will look at the above procedure, decide it's too difficult, and install an alternator! Pity!
Jerry
