1998 Lexus LS 400FACTORY OEM SERVICE PROCEDURE

Headlight Relay

Remove headlight relay (located in junction block, on left side of engine compartment in front of shock tower). Using an ohmmeter, check continuity between relay terminals. Continuity should exist between terminals No. 1 and 2. See Fig 1. Continuity should not exist between terminals No. 3 and 4. Apply battery voltage and ground between terminals No. 1 and 2. Continuity should exist between terminals No. 3 and 4.

Fig 1: Identifying Headlight Relay Terminals
G93F01686Courtesy of Β© TOYOTA, LICENSE AGREEMENT TMS1002
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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