1993 SC300, 160k miles, 1 year old battery, brakes recently replaced, O-ring recently replaced to fix oil leak.

First occurrence: nighttime driving 70mph on highway, AC on, radio on, headlights on. All interior and exterior lights (dashboard, radio, AC, headlights) turn off. Engine turns off. both for less than a second before turning on again. Continues to occur every now and then.

Second occurrence: 45mph city driving, AC on, radio on. When I brake, all interior lights flicker off/on. Engine turns off/on. both for less than a second.

Third occurrence: nighttime stopped at a 4-way stop, AC on, radio on, headlights on. All lights turn off. Engine turns off. All lights turn on. Engine remains off. I reset key in ignition and turn on the engine without a problem.

Fourth occurrence: driving 70mph on highway, heat on, radio on. All lights turn off, then on. Check Battery light flashes, disappears. Lights continue to turn off, then on.

After I parked, automatic locks weren't working.

Just wondering what fixes worked for other people.
Older posts point to battery connections, shorts.