I'd check for voltage and ground at the blower motor, when the problem is ongoing. Purple wire is voltage, orange is ground. If you have good voltage and ground with no blower action, suspect the blower motor.
Usually any smaller interior motor, when I take it off, I use jumper wires from battery for voltage and ground, just to see if motor still acts-up, if it does, it is a faulty motor. If you try something like that, do use an inline fuse on one of the jumpers, just in case.
Wednesday, January 5th, 2011 AT 9:23 PM