Rear wiper not working

What is your question?

I have an 05 envoy with a rear windshield wiper that doesn't work. The defrost works but only for the top half of the window. Wiper flinches in it's spot when the control dial is activated then doesn't move at all. Suggestions? Thoughts? It'd be great to get this thing working

What makes this problem better or worse?

Consistently not working

How long has your 2005 GMC Envoy had this problem?

Purchased in 2018, I've never seen it work