Charging Systems: Generator: Inspection: Rectifiers

Positive rectifier test 

Check for continuity between the positive rectifier and stator coil lead connection terminal with an ohmmeter. The ohmmeter should read continuity in only one direction. If there is continuity in both directions, a diode is shorted. Replace the rectifier assembly.

Fig 1: Checking For Positive Rectifier Continuity

Courtesy of KIA MOTORS AMERICA, INC.

Negative rectifier test 

Check for continuity between the negative rectifier and the stator coil lead connection terminal. The ohmmeter should read continuity in only one direction. If there is continuity in both directions, a diode is shorted, and the rectifier assembly must be replaced.

Fig 2: Checking For Negative Rectifier Continuity

Courtesy of KIA MOTORS AMERICA, INC.

Diode trio test 

Check the three diodes for continuity by connecting an ohmmeter to both ends of each diode. Each diode should have continuity in only one direction. If continuity is present in both directions, a diode is defective and the heat sink assembly must be replaced.

Fig 3: Checking Diodes For Continuity

Courtesy of KIA MOTORS AMERICA, INC.