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Stoplight Switch Circuit

  1. Ensure stoplights operate when brake pedal is depressed. Disconnect stoplight connector and remove stoplight switch. Using an ohmmeter, check for continuity between stoplight switch terminals. Continuity should exist between terminals No. 1 and 2. See Fig 1. Depress stoplight switch button. Continuity should exist between terminals No. 3 and 4. See Fig 1. Replace switch as necessary. If stoplight switch is okay, go to next step.
  2. Using voltmeter, measure voltage between ground and stoplight switch connector terminal No. 2 (White wire) and ground. If battery voltage exists, stoplight switch circuit is okay. If battery voltage is not present, inspect and repair circuit between stoplight switch, power source and ABS ECU.
Fig 1: Identifying Stoplight Switch Terminals
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