no brake lights

We need to start by checking the ground on the left frame rail behind the bumper. G415 is the ground and if it is dirty then that is going to be the issue.

I attached the wiring diagram below that will help with this. Here is a guide that will help with testing.

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

If this is not the issue, then the most likely cause is the turn switch as the power is fed through this. The third brake light is run through a different circuit so if this is working then the switch is most likely the issue.

Please run through this testing and see the wiring diagram below and let me know what you find.

Thanks