Rotor check
1. Check the rotor winding for damage. Check the resistance between the generator rings.
If the resistance is low, then there is a short circuit in the rotor (short circuit). If there is no connection, then the rotor winding is broken.
Resistance value: approximately 3.1 ohms.
2. Check the rotor winding for a short to ground. If the rotor winding is closed to the magnetic circuit, then the rotor should be replaced.
Stator check
1. Measure the resistance between the stator winding leads as shown in the figure below. If a winding break is detected, the stator should be replaced.
2. Measure the resistance between the terminals of the stator phase windings and the magnetic circuit, as shown in the figure below. If a short circuit of the phase windings to the magnetic circuit is detected, then the stator should be replaced.
Checking the rectifier unit
1. Check the resistance between the positive heat sink plate and each of the stator winding connection points. If "dialing" carried out in both directions, then the corresponding diode "broken". Replace rectifier.
2. Check the resistance between (-) heat sink plate and each of the connection points of the stator windings. If "dialing" carried out in both directions, then the corresponding diode "broken". Replace rectifier.
3. Check the condition of the three diodes. To do this, alternately measure the resistance of each of the diodes in the forward and reverse directions. If the diode "called" in both directions or "not ringing" in any direction, then such a diode is defective. If any of the diodes is defective, replace the rectifier unit.
Checking the brushes
1. Measure the protrusion of the brushes as shown in the figure below. If the protrusion of the brush is less than 2 mm, the brush must be replaced.
2. Unsolder the connecting wire. Take out the old brushes.
3. Install new brushes in the brush holder as shown in the figure and solder the connecting wires.