Diode (2.5 L Model)

CAUTION: There is the possibility of damaging the diodes if a mega-tester (used to measure high voltages) or a similar measuring instrument is used. Never use a mega tester or equivalent for this test.

Check for continuity between the diode lead and positive side heat sink. If resistance is 1 Ω or more only in the direction from the diode lead to the heat sink, replace the rectifier.

Fig 1: Identifying Diode Lead And Heat Sink (Positive Side)
Courtesy of SUBARU OF AMERICA, INC.
Check for continuity between the negative side heat sink and diode lead. If resistance is 1 Ω or more only in the direction from the heat sink to the diode lead, replace the rectifier.

Fig 2: Identifying Diode Lead And Heat Sink (Negative Side)

Courtesy of SUBARU OF AMERICA, INC.