Stoplight Switch
Disconnect stoplight switch connector (located on brake pedal support). Using an ohmmeter, check continuity between stoplight switch terminals. With switch pin released (brake pedal pressed), continuity should exist between terminals No. 1 and 2, and continuity should not exist between terminals No. 3 and 4. See Fig 1. With switch pin pressed (brake pedal released), continuity should exist between terminals No. 3 and 4, and continuity should not exist between terminals No. 1 and 2. If continuity is not as specified, replace stoplight switch and retest system operation.