I think I read that the speedo goes that way with an open circuit......meaning something is not connected. Most times that means the printed floppy circuit board on the back side of the cluster is messed up.
When I was swapping out the gauge set with a spare one I had on hand, apparently I rolled the assembly over during the install, causing gravity to pull the needle to the far right, which I did not notice during the install. Once it was there, it stays there apparently, even during use on the road.
When removing it, I notice the needle had rolled back over to the 0 MPH location. So I was careful to keep it that way while I reconnected the gauge set assembly.