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Yellow Light On, Red Light Off

  1. Attempt to retrieve trouble code. See RETRIEVING TROUBLE CODES  in this article. If trouble code was retrieved, go to appropriate code. If trouble code cannot be retrieved, ensure master cylinder connector is plugged in fully. If connector is fully plugged in, check RABS 20-amp fuse.
  2. If fuse is bad, check for short in wiring between fuse panel and control module connector. If fuse is okay, turn ignition off. Unplug control module. Turn ignition on. If Yellow light remains on, repair short in wiring between Yellow light and control module connector.
  3. If light goes off, measure voltage at control module connector pin No. 1 and at pin No. 9. If voltage is less than 9 volts at either pin, repair open circuit between fuse |panel and appropriate pin at connector or power source to fuse panel. If voltage is 9 volts or more, measure voltage at control module connector pin No. 2.
  4. If voltage is 8 volts or more, go to step 6). If voltage is less the 8 volts, measure voltage at both Purple/White wires on Bronco an F Series or Purple/White wire and at Purple/Yellow wire on all others, at fluid level switch. DO NOT unplug switch connector to check voltage. If voltage is 8 volts or more at one wire but less than 8 volts at other, replace master cylinder reservoir.
  5. If voltage is less than 8 volts at both wires, replace diode/resistor or repair open in indicator light power supply wire between fuse panel and instrument panel. Diode/resistor is located in Wiring harness on left front fender on Bronco II and Ranger. On Bronco and F Series, Diode resistor is located behind instrument panel. If voltage is 8 volts or more at both wires, check for open in Purple/Yellow wire or Purple/White wires.
  6. Turn ignition off. Reconnect control module connector to module. Turn ignition on. Measure voltage at Diagnostic connector. If voltage is less than one volt, check for short in Black/Orange wire between diagnostic connector and control module. If voltage is one volt or more, replace control module and retest system.
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