The rear window wiper stopped working on my Expy. What might I look for as the cause?

 

After the fuse, the motor. You may wind up with a dead battery, the motor is notorious for heading south in such a way that it is still drawing current. If the fuse checks ok, you should pull it to prevent the battery from draining.

 

for me, it was the multifunction switch. i'm on my 3rd one. Still have the original wiper motor

 

where is the multifunction switch?

 

Hanging off your steering column. Its the on/off switch for your wipers.

 

On my 2003 the pivot, that goes through the glass, for the wiper arm was the problem. It gets gummed up with corrosion so it's too hard for the motor to move the wiper. If you have a window that opens, pop it open and see how hard it is to manually move the wiper arm (it should be fairly easy). I burnt up a motor and almost did it to a second motor. It seems that the motor once started MUST complete a back and forth wipe. If the wiper arm hangs this process up the motor stays on even if the key is removed. The motor eventually burns out after being stuck like this for a while. You can buy a new wiper pivot on ebay if this is your problem. Search for rear wiper pivot.

See my post on cleaning the pivot:
https://www.ford-trucks.com/forums/1...l#post11251700