windshield wiper

my passenger side wiper won't work, you can see it try to move.

Does the driver side wiper move as normal?
If so, check the wiper linkage under the cowl vent grille. Wiper motor is linked to driver side wiper and that is linked to passenger side wiper.
Can you move the passenger side wiper by hand? (when wipers are not running).

//F

You didn't post the year of the truck but there is a nut under the rubber cab on the arm that tightens it to the shaft on the 2nd gen.