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Section 363 (Fog Light System): Inspection

WARNING: This page is about a different car, the 2004 Lexus GS 430 and 2004 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT FOG LIGHT SWITCH CONTINUITY 
    TESTER CONNECTION SPECIFICATION

    Switch position Tester connection Specified condition
    OFF - No continuity
    ON 11 - 12 Continuity

    If continuity is not as specified, replace the switch.

    Fig 1: Inspecting Fog Light Switch Continuity
    G03471051Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Connector disconnected: 

    INSPECT FOG LIGHT SWITCH CIRCUIT (See  LIGHT CONTROL SWITCH CIRCUIT  ) 

    Disconnect the connector from the switch and inspect the connector on the wire harness side, as shown.

    Fig 2: Inspecting Connector On Wire Harness Side
    G03471052Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TESTER CONNECTION SPECIFICATION

    Tester connection Condition Specified condition
    11 - Ground Light control switch TAIL or HEAD and dimmer switch LOW or HI Continuity

    If circuit is not as specified, inspect the wire harness.

  3. Connector connected: 

    INSPECT FOG LIGHT SWITCH CIRCUIT 

    Connect the wire harness side connector to the light control ant dimmer switch and inspect the connector from the backside, as shown.

    Fig 3: Inspecting Fog Light Switch Circuit
    G03471053Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TESTER CONNECTION SPECIFICATION

    Tester connection Condition Specified condition
    11 - Ground Light control switch HEAD and headlight dimmer switch LO and fog light switch ON No voltage
    11 - Ground Light control switch HEAD and headlight dimmer switch HI or FLASH and fog light switch ON Battery positive voltage

    If circuit is not as specified, inspect the wire harness.

  4. INSPECT FOG LIGHT RELAY CONTINUITY 
    TESTER CONNECTION SPECIFICATION

    Condition Tester connection Specified condition
    Constant 1 - 2 Continuity
    Apply B+ between terminals 1 and 2. 3 - 5 Continuity

    If continuity is not as specified, replace the relay.

  5. INSPECT FOG LIGHT RELAY CIRCUIT (See  INSPECTION  ) 
    Fig 4: Inspecting Fog Light Relay Circuit
    G03471054Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002