NO TAIL LIGHTS?

You must have a broken wire (brown) going to the rear of the car, here is a guide to help test for power and the tail light wiring diagrams so you can see how the system works and which wires to test.

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

Check out the images (Below). Please let us know how it goes