Try tapping the side of the wiper motor with a hammer. If it works after tapping with a hammer than you know its a bad motor. If it still doesn't work it could be wiring, the switch or the motor itself. Simple way to rule it out. I actually just had that issue last week but I have a Dodge. Turned out to be the motor.
I honestly dont even think you can get a hammer up in there without some disassemble first. Have you done this one a van? WHY couldn't the motor be where they are on the trucks? lol