Tail lights do not work when I have my headlights on

There is a a fuse for these lamps but it is also for the license plate lamp so if that is out as well then the fuse is the issue. Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Also, here is a guide that will help with testing the voltage as that is what we need to do in order to figure out what the issue is:

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

Below is the wiring diagrams from the manual that will help with this in order to figure out what the possible issue is. However, I suspect you will find the fuse is the issue if the plate light is out as well.

Please let us know if you have other questions. Thanks