Where is1990 Lexus LS400 Fog light switch location?

SOURCE: 2001 LEXUS IS 300 FOG Lights

as you have a multimeter .... check that there is voltage going to the lamps when power is on for them. as well locate the relay for them...

Robert

SOURCE: 1997 Lexus LS 400 Fuel Filter location

The fuel filter is located under the vehicle on the left side before the rear axle.

SOURCE: Lexus LS400 1996 heater not warm

Check your coolant level sounds like it might be low.

SOURCE: Replace/fix starter on 1991 Lexus LS400

Not too bad. Not much room, just enough to drop the starter. It is probably easier to go up through exhaust if you can get your exhaust shield off the manifold .

SOURCE: Where is the computer box in the Lexus LS400

There are 11 electronic control units(ECU) located in the dash area. They are as follows.
Engine + trans. ecu. behind right side of the dash.
Abs + traction ecu. beside the engine ecu.
electric mirror ecu. behind upper right side of dash.
SRS ecu. behind dash at console.
Shift lock ecu. in center console near shifter.
Power seat ecu. under drivers seat.
progressive power steering ecu. behind left dash left of column.
Steering column tilt + telescopic ecu. behind left dash above column.
Anti-theft ecu. behind far left of dash.
Cruise control ecu. just below the anti-theft ecu.
My guess is you are looking for the engine ECU but you may be
looking for 1 of these in the future. Hope this helps.