Hi Black Widow,
Thats my posts that Archon reffered you to. Mine was doing the same thing and all it turned out to be was a hidden ground prong on the bottom side of the connector that was not making contact with the motor housing to create a ground. Its really a simple fix and will save about $200 for the costs of a new motor.
Heres how to proceed:
1. Pull the panel under the glove comp off, should be 2 screws and a push-in (center) pin to remove. Unhook the light and lay out of the way
2. Turn on the car and the AC/heat (make sure you fan is on via the display, it should ramp up slowly), if not increase the fan speed to max. If the motor is not working you will not hear anything, you only have to watch the climate control panel for the fan speed to increase. Once its at high, jiggle the blk connector going into the bottom of the fan, it should be on the side nearest the pass door. Move it up and down and sideways, if fan starts to work, you have the same issue I did. Next step
3. turn everything off, remove connector going into fan, remove cooling tube in rear bottom of fan. There are 3 screws mounting the fan, they are not fun to get to, but not terrible either. Remove these and drop the fan straight down out of the dash. You will have to move some additional wiring to the side to do this and get it completely out, but you do not have to unhook anything to do this, just move the wiring
4. Once the fan is out, there are two phillips screws on the bottom of the motor, remove the and with a straight screw, gently pry the rear cover off. You have to do the very delicately as your motor brushes are here. After the cap is loose, work it over the brushes until its completely off the motor assembly.
5. I'm betting its pretty dirty in there? Have some electrical grade contact cleaner (no flash point, non-flammable), and spray, spray spray. Everything, then take an airline and blow everything out.
6. Now remove the connector assembly from the motor cap. Make note how it is in as it only works one way.
7. Now look at the bottom of the connector, the side that was on the very rear of the motor. There should be a metal prong bent over the connector housing. This has to make contact with the motor hoousing to provide a groung to the motor itself. Mine was bent and not making continuous contact. When I'd hit a bump or something, it would occasionally come on. This was the prong hitting against the housing.
8. My fix was to very lightly lift the prong up, not much, just enought to twist a piece of 18 guage speaker wire (stripped of course) under the prong, with about 1/4 inch of it hanging out past the prong. I then soldered this in place and bent the prong back to its original position. You could probably do it without soldering, but I liked the security of not doing it again.
9. Next you slide the connector assembly back over the motor shaft and brushes and seat into place. Make sure you again do this with the right side facing the motor end cap that you're getting ready to reinstall.
10. Now with the brushes seated, reinstall your end cap assembly making sure that your new ground wire is "pinched" by the motor cap cover and the connector plug assembly. You should be able to see a small bit of wire sticking out, this is good. reinsert the 2 phillips screws and tighten up. After all is tight, you can take a knife and gently push the exposed wire back between the motor housing and connector housing. This again just ensures a tight fit.
11. Reassemble back in car, don't forget the cooling hose in the rear, and insert connector. Turn on AC and smile
Hope this helps