Ford Repair: 2002 ford windstar rear a/c & heat blower motor, blower motor resistor, ford windstar

Question
The rear blower motor on my 2002 ford windstar does not work, I have power to the wire that connects to the motor.
The day before I unplugged the motor then plugged it back in and it worked. The next day it didn't work at all.
Is it the motor or blower motor resistor?

Answer
do you have a ground to the motor it has to have both to work and is your voltage high enough-check connection make sure wire isn't broke wiggle it while key and fan switch is on-you know you have power take a voltmeter and make sure it is over 10 volts-check the other wire for ground-to do this connect black wire from voltmeter to a ground point and red wire to other side of blower connector opposite power wire you hope to have a reading of 0 but .05 or less would be ok. if all this checks out it should be blower. if not the switch or resistor.