Headlights and fog-lights are inoperable.
The headlights and fog-lights are controlled by the combination switch. This switch signals the the Body ECU to activate the headlamp relay. The headlamp relay receives its battery power from a 50amp “Main Fuse” that is hot at all times. The fog-lights and headlights have separate relays along with DRL relays. I wouldn’t think all the relays went out at the same time. I would rather suspect the switch, the fuse or the ECU. You may use the provided wiring diagrams to help better understand the circuit.
Headlight Wiring Diagram (1 of 2) 2001 Lexus RX300
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