SethP

Anyone seen this before? The bulb is brand new, it works fine if you hit the brake, but not if you the lights are just on. The other brake light/running light works fine, it's just on this one side.

bob2200

It sounds to me like maybe a dual-filament bulb. Check that the wire contacts on the bulb aren't bent out of position. Also, switch right and left bulbs to eliminate the chance of a burned out filament being the problem.

salimshah

Tail light and brake-light have different filament, encapsulated in one glass shell. Tail light should light up on the first stop of the light switch and the brake lights light up when you press the brake pedal.

Both the tail light and the brake lights are independent of ignition switch position. [not in every car, but yes in Lexus line]

For replacement, match the wattage, else the light out sensor will trip.

Wiring/bulb confusion stems form an ingenious implementation of switching on/off the brake lamp as a turn signal [I term it the American no-yellow turn signal]. The trailer wiring hitch for Lexus needs that conversion as the trailers use the same bulb for brake and turn.

Salim