Window Washer Level Warning Light
WARNING: This page is about a different car, the 2003 Lexus GS 430, 2003 Lexus GS 300, 2002 Lexus GS 430, and 2002 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect the connector from the warning switch and ground terminal on the wire harness side connector. See Fig 1. With the engine running, check that the warning light lights up. If the warning light does not light up, inspect the bulb or wire harness.