"A" circuit generators (most GM models) strike the battery and armature posts together using a jumper wire or a pair of pliers, (spread the handles) and touch the two posts together briefly. You should see a small spark then you are done. You need to do this every time you remove either the generator or regulator for service.

"B" circuit generators (most Ford Products) – DISCONNECT the FIELD wire from the regulator and strike it onto the BATT post on the regulator. When you see some small sparks you are done. Reconnect the field wire to the regulator. You have to remove the wire to polarize a “B” circuit generator. DO NOT use a jumper wire. You will need to do this every time you remove either the generator or regulator for service.

"A" circuit or "B" circuit…?
Look at the back of the generator; if the generator field wire is connected to the INSULATED brush you have an “A” circuit. If the field coil wire is connected to the NON-INSULATED Brush or Ground, you have a “B” circuit generator.