PC7

- Key OFF.

- Remove warning lamps.

- Key ON.

- Check for voltage between warning lamp bulb socket (+) and known good chassis ground.

- Is B+ present?

YES -- Open lamp ground circuit. Service open in Circuit 57 (BK) between ECU Pin 20 and ground. Service open in Circuit 570 (BK/W) between ECU Pin 1 and ground. Go to PC2. PC2

NO -- Open power feed circuit. Service open in warning lamp power feed circuit between warning lamp fuse and warning lamps. Go to PC2. PC2