You may have a rectifier/regulator. If you can access it you can check for AC voltage using a volt meter. If there's ac voltage switch your meter to dc volts and check for dc voltage should see about 14 dc volts. The ac may be 30 volts and if you have ac volts I think your rectifier is shot. Here's a picture. Hal
PS: You need the engine running at 1/2 throttle or better. Be careful where you place your hands or fingers.