I have been trying to get into the wiper housing. The motor sounds like it is running, but I have no movement in my wiper blade. I suspect the gears are stripped, but I cannot get far enough into it. There is a pesky screw that appears to be partially stripped, but may also require some type of special tool. I can't tell. Is anyone familar with this issue and have any advice on how to get into the housing and replace the gears? I'm a bit of a novice, so any help would be greatly appreciated.

 

probably just the 13 mmnut and maybe just need tightening but you have to remove the wiper assembly to access nut.