FixVault

Test 63A - Diagnosing Parking Lamp Switch

NOTE: For connector terminal identification and wiring diagrams, see BODY CONTROL COMPUTER  section in this article. Perform TEST VER-1  VERIFICATION TEST after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module connector.
  1. Turn ignition off. Disconnect headlight switch connector. Disconnect Body Control Module (BCM) connectors. Using scan tool in ohmmeter mode, check resistance of headlight switch 8-pin connector terminal No. 5 (Orange/Dark Blue wire). If resistance is less than 5 ohms, repair short to ground in Orange/Dark Blue wire. If resistance is 5 ohms or greater, go to next step.
  2. Using an external ohmmeter, check resistance of Orange/Dark Blue wire between headlight switch connector terminal No. 5 and BCM Bone connector terminal No. 4. If resistance is 5 ohms or greater, repair open Orange/Dark Blue wire. If resistance is less than 5 ohms, go to next step.
  3. Using scan tool in ohmmeter mode, check resistance of headlight switch 8-pin connector terminal No. 2 (Black wire). If resistance is 5 ohms or greater, repair open Black wire. If resistance is less than 5 ohms, go to next step.
  4. Using an external ohmmeter, check resistance between parking lamp/headlight switch terminals No. 2 and No. 5. See Fig 1 . Slowly rotate dimmer switch from low to high. If resistance does not change from more than 9000 ohms to less than 2000 ohms, replace parking lamp/headlight switch. If resistance changes from more than 9000 ohms to less than 2000 ohms, replace BCM.
Fig 1: Testing Parking Lamp/Headlight Switch
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