GS300 & GS430
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2001 Lexus RX 300, 2001 Lexus LX 470, 2001 Lexus LS 430, 2001 Lexus IS 300, and 2001 Lexus GS 430. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Disconnect 18-pin combination switch connector. Using an ohmmeter, check continuity between connector (harness side) terminal No. 16 (White/Black wire) and ground. Also, check continuity between connector (harness side) terminal No. 17 (White/Black wire) and ground. If continuity exists at both terminals, go to next step. If continuity does not exist at either terminal, repair wire harness between combination switch and ground connection. Retest system operation.
- Using an ohmmeter, check continuity between connector (harness side) terminals No. 11 (Green/Black wire) and No. 18 (Green/Black wire). If continuity exists, go to next step. If continuity does not exist, repair wire harness between combination switch. Retest system operation.
- Reconnect 18-pin combination switch connector. Turn ignition on. Using DVOM, measure voltage by backprobing rear of combination switch connector between the following terminals and ground with light control/dimmer/foglight switch in specified position. See LIGHT CONTROL/DIMMER/FOGLIGHT SWITCH CIRCUIT VOLTAGE (GS300 & GS430) table. See Fig 1. If voltages are not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, check light control/dimmer/foglight switch. See COMBINATION SWITCH under COMPONENT TESTS. Replace combination switch as necessary. Retest system operation.LIGHT CONTROL/DIMMER/FOGLIGHT SWITCH CIRCUIT VOLTAGE (GS300 & GS430)
Check Voltage Between Ground & Terminal No. Switch Position Voltage 8 Flash Or HEAD & High Beam Zero 8 HEAD & Low Beam Battery 9 HEAD Battery 11 HEAD, Low Beam & Fog Light Switch ON Zero 11 HEAD, High Beam Or Flash & Fog Light Switch ON Battery 12 OFF Or TAIL Zero 12 HEAD Battery 13 OFF, TAIL Or HEAD Zero 13 AUTO Battery 14 OFF Or TAIL Zero 14 HEAD Battery 15 OFF Zero 15 TAIL Or HEAD Battery 18 HEAD, Low Beam & Fog Light Switch ON Zero 18 HEAD, High Beam Or Flash, & Fog Light Switch ON Battery