They are not easy to fix. I’ve spent many hours under my passenger seat. My recliner stopped working. After a lot of diagnoses, I determined the motor for the recliner puked. Then the switch to move the seat forward and back quite working. Wires are everywhere under there, so it’s difficult to determine what’s what. And you have little room to work with.
What I learned is you need to check all the wires under there to make sure all are undamaged and you have power when needed. You may be on your back on the floor, for a long time.
In your case since nothing works, you need to get out your volt meter to determine if power is present. If not, you might get lucky and just need a new fuse, or find a connector disconnected.
2008 Monaco Dynasty Squire
Paul & Luci