a) Loose alternator belt. b) Damaged rectifier diode. c) Weak contact of graphite brushes. d) Short circuit of a partial winding of the rotor or stator.
a) Tighten the belt or replace the worn belt with a new one. b) Replace the damaged rectifier diode with a new one. c) Replace. d) Restore or replace the rotor or stator winding with a new one.