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Foglights Will Not Turn On

  1. Using scan tool, select BODY INPUT/OUTPUTS. Monitor FOGLIGHT SWITCH STATE. Turn foglight switch from ON to OFF position. If FOGLIGHT SWITCH STATE changes when switch is operated, go to next step. If FOGLIGHT SWITCH STATE does not change when switch is operated, go to step  12.
  2. Inspect fuse No. 24 (15-amp) located in junction block. See Figure. If fuse is blown, go to next step. If fuse is okay, go to step  6.
  3. Remove foglight relay from junction block. Disconnect a foglight bulb connector. Using DVOM, measure resistance of Light Blue wire between foglight bulb connector and foglight relay socket terminal No. 87. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open in Light Blue wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  4. Remove foglight relay from junction block. Install a known-good relay. Operate foglights. If foglights do not operate correctly, go to next step. If foglights operate correctly, replace defective foglight relay. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  5. Using DVOM, measure resistance between ground and foglight relay socket terminal No. 87 (relay output circuit). If resistance is less than 5 ohms, repair relay output circuit for short to ground and replace fuse No. 24. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS. If resistance is 5 ohms or greater, replace fuse No. 24. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  6. Remove foglight relay from junction block. Disconnect a foglight bulb connector. Using DVOM, measure resistance of Light Blue wire between foglight bulb connector and terminal No. 87 on foglight relay socket. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open in Light Blue wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  7. Install a known-good foglight relay. Operate foglights. If foglights do not operate correctly, go to next step. If foglights operate correctly, replace defective foglight relay. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  8. Turn ignition on. Voltage is assumed to be present at junction block White 3-pin connector C5 terminal No. 3. See Figure. Using DVOM, measure voltage between ground and B+ terminal on fuse No. 24 socket. If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, replace junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  9. Turn ignition off. Remove foglight relay. Remove Body Control Module (BCM) from back of junction block. See Figure. Using DVOM, measure resistance between BCM junction block connector terminal No. 2 and foglight relay socket terminal No. 85. See Figure. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, replace junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  10. Using DVOM, measure resistance between ground and foglight relay socket terminal No. 85. If resistance is 10 ohms or greater, go to next step. If resistance is less than 10 ohms, replace junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  11. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  12. Using scan tool, select INPUT/OUTPUTS under BODY. Monitor FOGLIGHT SWITCH STATE. Disconnect left multifunction switch connector. Connect a jumper between multifunction switch connector terminals No. 1 (White/Tan wire) and No. 4 (White/Dark Green wire). If FOGLIGHT SWITCH STATE does not change when jumper wire is connected, go to next step. If FOGLIGHT SWITCH STATE changes when jumper wire is connected, replace left multifunction switch. See appropriate STEERING COLUMN SWITCHES article. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  13. Turn ignition off. Disconnect BCM connector C2. See Figure. Using DVOM, measure resistance between ground and multifunction switch connector terminal No. 1 (White/Tan wire). If resistance is less than 5 ohms, repair short to ground in White/Tan wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS. If resistance is 5 ohms or greater, go to next step.
  14. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
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