brake lights not working, only center lights up

Hello,

It sounds like the flasher module is out which causes this problem. The hazard switch is the flasher. here are wiring diagrams so you can see how the system works and how to replace the switch:

To be sure here is a guide to show you how to check for power:

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

Please run down this guide and report back.