Bench Testing: Diodes
Using an ohmmeter, check continuity of all diodes in both directions. Ensure continuity exists in only one direction. See ALTERNATOR DIODES CONTINUITY table. If continuity exists in both directions, diode is shorted. See Fig 1. If continuity is NOT present in either direction, diode is open. If any diode is defective, replace entire diode assembly.
ALTERNATOR DIODES CONTINUITY
| Positive (+) Lead | Negative (-) Lead | Continuity |
|---|---|---|
| Diode Plate | Diode Terminals | Yes |
| Diode Terminals | Diode Plate | No |
| - Diode Plate | Diode Terminals | No |
| Diode Terminals | - Diode Plate | Yes |