Adjustable gas/brake pedals clunk but not move on 03 Crown Victoria

My 2003 Ford Crown Victoria came with adjustable gas and brake pedals. There is a button on the dashboard to move the two pedals (together) toward or away from the driver. When I push the button in either direction, the pedals clunk. I can feel them trying to move but can’t. When I put my foot on the pedals when I push the button, it feels like there is something like a stop blocking the pedals from moving, so there is a clunk. Since the pedals are trying to move, it can’t be a fuse or relay problem.

What could be wrong with this? I have never had a car with adjustable pedals and never had to fix them.

It’s time to visit a good, independent mechanic. They will be able to tell you exactly what’s wrong with the pedals and the cost to fix them. I have never owned adjustable pedals either and have never needed them. If the repair cost is high, I would leave them as-is and pull the fuse or disconnect the switch.