I recently purchased a 2000 4 Runner that has developed an issue with the right blinker. The blinker works properly until I depress the brake pedal. Depressing the brake pedal causes the right blinker to stay on steady regardless of whether I had the blinker on prior to the brake or not. I also noticed applying the right blinker while the cruise control is engaged will shut off the cruise. Any clues would be greatly appreciated.

 

DEfinitely a crossed wire. I would check first back by the tailight, see if the blinker/brakelight wires cross. Seems to me...that the brakes give constant power to the signal light, instead of the intermittent, and somehow the blinker is telling the cruise you hit the brakes.... brake light/turn signal wires seems a decent place to start...

 

I currently have the rear door threshold and trim off of my 2000 Limited.
I have a similar problem. If I step on the brake with the right turn sig on it flashes twice as fast and shorts out the ABS. Same thing if I step on the brake in reverse.
I'm going to start testing wire continuity today or tomorrow. I'll let you know what I find.

 

This is Toyota's way of telling you you have a bulb out. Seriously...check them. I'll bet you one is out, dim, or has a bad connection.