Brake lights are not working

Welcome to 2CarPros.

My first suspect is a ground issue. The third high mount brake light has a different ground location than the lower tail lights, and both left and right use the same ground.

With that, I need you to locate the ground for the lights in question. The ground will have black wires and is located in the left side of the cargo compartment. You will need to remove a few things to locate it.

Take a look at the attached picture. It is a portion of the wiring schematic that shows what I am referring to. Picture 2 is the high mounted light that is on a different ground.

Here are some links which explain how to check wiring and use basic tooling:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

Now, since the high mount light works, that tells me it isn't a fuse issue or brake light switch related issue. Thus, my first suspect is a bad ground which is common to both of the non operational lights.

Let me know what you find or if you have other questions.

Take care,
Joe