Classic/Antique Car Repair: MGA Generator, pig tail, small pig

Question
I am rebuilding a 59 MGA coupe.  I cannot get the generator to work, and have tried the original plus two new ones from an MG parts store.  Car is positive ground, and I did the procedure to make the generator positive ground, but the battery won't charge.  I tested the generator at the outputs but no indications.  Is there a way to test a positive ground generator (on or off the car) to tell if it works?

Answer
Hi Trey,

The Lucas DC genreator is easy to test on the car. First confirm that your batteries are connected correctly and have some what of a charge in them. Disconnect both wires from the generator and make up a test lead of at least 12 ga. wire. Connect a smaller wire (14 ga) pig-tail to the end of the large wire so you now have two ends to work with. Attach the two ends of the large wire to the two posts on the back of the generator. (large wire to the large post and small pig tail wire to the small post) Now, with the other end of the large test wire touch the power post (neg.) of the manual starter switch and hold it on the post for 3 to 4 seconds and remove it. repeat this several times. This polerizes the generator. A rough partial test of the generator can be made at this time by removing the generator belt and make the contact again. The generator should run like a slow electric motor (IN THE DIRECTION OF ENGINE ROTATION) This is not a full test of the generator but it is a starting point.
Now make sure the wires you removed from the gen do not make contact with anything and install a volt meter from the "hot" post of the starter switch to a good ground. You should read battery voltage. With your belt back on and your end of the test wire in you control have someone start the engine and set it at a fast idle (not too fast) 1500 RPM would be OK. Look at your volt meter, you should see battery voltage, and touch the hot post of the starter switch with the end of the test lead and read the volt meter. It should read about 15 volts. (DO NOT LEAVE THE TEST LEAD ON THE HOT POST FOR MORE THAN A FEW SECONDS)
If you do not show about 15 volts or more, your generator is not working. If you do see about 15 volts or more shut the engine off and remove your test lead and reconnect the original wires up to the generator and with your volt meter still connected start the engine and set the RPM up again to 1500 + and read the volt meter. It should read 13.8 to 14.5 volts. If is does everything is working correctly, if it does not, your regulator or wiring is at fault. Check the wiring on the regulator. "F" = field (the small wire on the gen.) "A" = power (neg. battery) "D" = large post on the gen. "E" = ground (pos. battery)
I hope this helps.
HMF