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Rear Defogger Relay Shorted High

  1. Access junction block on left side of instrument panel. See Figure. Remove rear window defogger relay. Connect test light between rear window defogger relay cavities No. 85 and 86 in junction block. See Figure. Using scan tool, activate R DEFOG RELAY on and off. If test light does not react to scan tool activation, go to next step. If test light flashes on and off, replace rear defogger relay. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  2. Turn ignition off. Disconnect Body Control Module (BCM) from junction block. See Figure. Turn ignition on. Using DVOM, measure voltage between rear window defogger relay cavities No. 85 and 86 and ground. Voltage should only be indicated at one terminal. If voltage is less than one volt at each terminal, go to next step. If voltage is greater than one volt at each terminal, replace junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  3. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
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