hbaldwin

1999 ES 300 - Last night with auto headlights on, sitting at a stoplight, then the headlights turned off and would only come back on if I moved stalk selector from AUTO to ON. High beams would not work either pushing stalk forward or all the way back. When we got home and parked, we opened doors and noticed that dome lamp and door interior courtesy lamps would not light. After exiting, tried to lock the car by the rocker switch on the driver door armrest and it didn't work either.
Now, in the morning after, all is working as it should. Both low beams and high beams, interior dome lamp and door interior courtesy lights, and electric lock actuators. Everything works now.
I've Google searched trying to discover what component is common among these items to no avail. I'm guessing it's a relay going bad? If you can help me identify the culprit and the location, that would be great.

LeX2K

Has the battery been checked?

hbaldwin

I've not checked it with a voltmeter, but the car starts right up every time, and the headlights are bright. The battery was new in September '23

LeX2K

Intermittent problems like this require checking of grounds, fuses and connectors for water damage, rodent damage etc.

Don't rule out a problem with the battery, either the battery itself or terminals and battery posts. Electrical problems like to show up when things get warm and start working again when cold.