When ignition key is off – brake lights function normal, depress pedal brake lights come on take foot off pedal brake lights turn off.

When ignition key is set to accessories position – brake lights function normal, depress pedal brake lights come on take foot off pedal brake lights turn off.

When ignition key is set to on position, w/engine off – brake lights function normal, depress pedal brake lights come on take foot off pedal brake lights turn off.

When ignition key is set to on position, w/engine on – brake lights do not function normal, depress pedal brake lights come on take foot off pedal brake lights stay on. Pressing the brake pedal multiple time has no effect on getting the brake lights to turn off. Found several ways to get the brake lights to turn off when stuck on, remove brake light fuse #37, disconnect battery or press brake pedal multiple times when key is removed from ignition.

All of the above is repeatable. Recent history of vehicle, car sat outside unused for several hot rainy months. Noticed steam on inside of windows on hot summer day. Opened the vehicle door to witness standing water in both front footwells. Identified the “infamous sunroof drain holes” were clogged.

Removed brake light switch and bench test, appeared to function okay. However, replaced with new $30 Switch since this vehicle has almost 200k on her. The conditions were unchanged from this switch replacement.

I do not have visible hitch or harness. I suspect corrosion somewhere is causing bleed over. Has anyone run across this?

 

I don't know if it can cause this but some people have had issues with the brake light sensor module
https://www.clublexus.com/forums/rx-...or-module.html

 

There is a fluid level sensor in the master cylinder. It can be as simple as fluid level fallen low to trigger it or the sensor itself can be on the fritz.

Salim

 

Salim are you talking about the brake light indicator in the dashboard?
OP says the brake lights themselves get stuck on when he depresses the brake pedal with the engine running.

 

My bad...
The actual brake lights in the back, should be independent of ignition position. Even without the key they should light up when the pedal is pressed. They are hot wired.
Also there are more than one switch on the brake pedal. [that is what I recall, please confirm]. Just make sure you test all of them [both?]

Salim