WARNING: This page is about a different car, the 2000 Lexus SC 400, 2000 Lexus SC 300, 2000 Lexus LS 400, 2000 Lexus GS 400, and 2000 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Cruise Control System Wiring Diagram (GS300)
Fig 2: Cruise Control System Wiring Diagram (GS400)
Fig 3: Cruise Control System Wiring Diagram (LS400)
Fig 4: Cruise Control System Wiring Diagram (SC300)
Fig 5: Cruise Control System Wiring Diagram (SC400)