1998 Lexus ES 300FACTORY OEM SERVICE PROCEDURE

Power Main Relay

Remove relay (located in junction block, on left side of instrument panel). See Fig 1. Replace relay if it does not operate as follows:

  • No continuity should exist between terminals No. 3 and 5.
  • Apply battery voltage and ground between terminals No. 1 and 2. Continuity should exist between terminals No. 3 and 5.

Fig 1: Identifying Power Main Relay Terminals
G97D04325Courtesy of Β© TOYOTA, LICENSE AGREEMENT TMS1002

Remove master switch. Check for continuity between specified terminals of master switch with switch in indicated position. See Figure. See MASTER SWITCH CONTINUITY TESTΒ  table. If continuity is not as specified, replace master switch.

MASTER SWITCH CONTINUITY TEST

Window Switch & Position Window Lock Switch Position Continuity Between Terminals No.
Driver's Switch
Off (Neutral) (1) 1, 6 & 13
Up (1) 1 & 13; 6 & 7
Down (1) 1 & 6; 7 & 13
Right Front Switch
Off (Neutral) Unlock 1, 5 & 12
Lock 5 & 12
Up Unlock 1 & 5; 7 & 12
Lock 7 & 12
Down Unlock 1 & 12; 5 & 7
Lock 5 & 7
Left Rear Switch
Off (Neutral) Unlock 1, 9 & 10
Lock 9 & 10
Up Unlock 1 & 9; 7 & 10
Lock 7 & 10
Down Unlock 1 & 10; 7 & 9
Lock 7 & 9
Right Rear Switch
Off (Neutral) Unlock 1, 11 & 14
Lock 11 & 14
Up Unlock 1 & 14; 7 & 11
Lock 7 & 11
Down Unlock 1 & 11; 7 & 14
Lock 7 & 14
(1) Position does not affect driver's switch.
Factory Service Tools

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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.