Re: rear windshield wiper arm not functioning......
Bad weather seal perhaps? If the motor attempts to move there's tension somewhere along the line. It won't hurt to take the inner hatch panel off, carefully peel back the weather barrier and have a look as the assembly. If you do this, it'd be good to lube the door lock mechanism as well. You can also attempt to Google the problem, or, check online for a free copy of the factory service manual (FSM). Keep us posted.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!