LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2005 >> SC 430 >> Repair and Diagnosis >> Electrical >> Horns >> Horn >> Horn System >> Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Horn System: Inspection

  1. INSPECT FUSE (HORN) 
    1. Measure the resistance of the HORN fuse.

      Standard: Below 1 Ω 

      If the result is not as specified, replace the fuse.

      Fig 1: Inspecting Fuse (Horn)
      G02958773Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. INSPECT HORN RELAY (Marking: HORN) 
    1. Remove the HORN relay from the engine room No. 2 R/B.
    2. Measure the resistance of the relay.

      Standard: 

      HORN RELAY (Marking: HORN)

      Tester Connection Specified Condition
      3 - 5 10 k ohms or higher
      3 - 5 Below 1 ohms (when battery voltage is applied to terminals 1 and 2)

      If the result is not as specified, replace the relay.

      Fig 2: Inspecting Horn Relay
      G02958774Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT LOW PITCHED HORN ASSY 
    1. Apply battery voltage and check operation of the horn.

      OK: 

      LOW PITCHED HORN ASSY

      Measurement Condition Specified Condition
      Battery positive (+) Terminal 1
      Battery negative (-) Horn bracket      		 Horn sounds

      If the result is not as specified, replace the horn assy.

      Fig 3: Inspecting Low Pitched Horn Assy
      G02958775Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT HIGH PITCHED HORN ASSY 
    1. Apply battery voltage and check operation of the horn.

      OK: 

      HIGH PITCHED HORN ASSY

      Measurement Condition Specified Condition
      Battery positive (+) Ω Terminal 1
      Battery negative (-) Ω Horn bracket      		 Horn sounds

      If the result is not as specified, replace the horn assy.

      Fig 4: Inspecting High Pitched Horn Assy
      G02958776Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
scientia non olet · About LEMON Manuals