Front drivers wiper not working

I have the same problem. When I removed the drivers side wiper arm, I found that the nut that held the arm in place was only finger tight, which allowed the arm to raise slightly off the splined shaft. This caused the shaft to strip the splines out of the wiper arm.. after inspecting and cleaning the shaft, it appears that the splines on the shaft are still in decent shape. You may need to only replace the wiper arm. About $50 at a few online toyota parts sellers. replacing it is simple and requires only a flat blade screwdriver to remove the black cap off the nut, and a wrench to remove and replace the nut. simply remove the nut, and pop off the wiper arm. push the new arm onto the splined shaft pointing the same place as the passenger side wiper, then tighten the nut down. I would also suggest wiping the metal shavings off the splined shaft with some sort of abrasive pad, like scotchbrite, before putting the new wiper arm back on. I hope this helps.