Isolation Diode Testing
- Connect a self-powered test light to indicated test points. See Fig 1 . Refer to Electronic Back Light EBL ISOLATION DIODE for proper response of continuity light and polarity.
- If diode is installed backwards or has failed in the shorted mode, activation of the EBL and indicator light will result when A/C or defroster control is engaged. Perform the same test for A/C isolation diode.
- Refer to A/C ISOLATION DIODE for proper response of continuity light and polarity. If diode is installed backwards or has failed in the shorted mode, the A/C clutch will energize when EBL is turned on.
- Should both diodes be shorted, the Stop Idle Solenoid (SIS) could be shorted, resulting in damaged EBL overlay wiring, damaged SIS wiring, or open fuse in cavity 16. If so, repair or replace shorted SIS and affected parts.