Rear liftgate won't open

It sounds like you have a fuse or a relay that is out I have pulled up the wiring diagrams for you so you can do some testing. Here is a guide to show you how to get started.

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

and

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

Please run some tests and get back to us so we can continue helping you.

Cheers, Ken