Hello, I can see why this circuit is a bit confusing, I'm going to post the aftermarket wiring diagrams to show what's probably going on here but will check the OEM diagrams to verify these are correct. But to begin with you'll have to locate this Brake light failure sensor, it looks like on pin 3 (green wire) is for the two side brake lamps, and the third (middle) is on a different circuit, why they do this I'm not sure, but I will pull up the rest of the diagrams to explain it all.
On diagrams 4 and 5 is the brake lamp circuit including the sensor, as you can see the third brake lamp power comes directly from the Brake pedal switch, whereas the left and right brake lamps power comes through this sensor first then branches out to the bulbs. Thats why only the 3rd lamp is working. Are you getting a message on the dash saying a brake lamp is out?
Also check this number 9 Drivers Fuse 10amp.
So, on this sensor, power should come in on pin 1 from the brake pedal switch on a white/black wire and go out to the two brake lamps on pin 3 a green wire. I would also verify that pin 6 has power with the key On, and pin 5 has Ground (black wire).
If you have a 12v test light, I would use that for testing, that way we know the circuit can handle some current flow,
On diagram five there are two ground wires for the right and left bulbs, I have the locations of those grounds if they are needed. And any questions just ask.
Images (Click to make bigger)
Monday, November 21st, 2022 AT 11:35 AM