BMW Repair: A/C Heater Blower, wiring loom, screw driver

Question
I have a 2000 323ci, and the A/C blower only works when outside temps are fairly cool (below ~80 degrees.  During this time everything works as designed including the varibale fan speeds.  When it is hot outside (above ~80 degrees), the blower fan will not turn on at all.  Any ideas would be appreciated.

Thanks,
Doug

Answer
Doug, This is most likely a faulty final stage resistor for the Blower motor. Please replace it. Part should be about $80-110. Very common failure due to poor heat disapation of original construction metal. New part is updated and much better. Replacement will require you work in a tight space.
You need:
Philips #2 screw driver
T-20 Torx driver
Good flash light (smaller is better)

Remove Glovebox
Open box and remove three philips screws on across top. Remove one screw bolted on bottom corner on underside of box. Remove two screws on left and right of opened box recessed a bit. pull box out and diconnect box light connector and note routing as you remove wires. Repeat for flashlight charger socket connector and wiring. Move box assemble aside. Remove black plastic panel and footwell light. Note slots panel fits in for reinstallation. Up and left toward heater/evaporator box is the main wiring loom. There is a stepper motor with a steel rod connected to it right by the loom. The Final Stage is inboard of the stepper motor. Remove the A/C footwell duct. I pry the upholstered console corner covering the duct outward and back to remove the duct. If you hear a crack while pulling the console back you are okay, you didn't damage anything. Remove Duct. It must fit both connections when you reinstall it. If you don't feel like removing the duct, fine I do it to give myself more room. Remove the T-20 screws on the black plastic bracket toward the stepper motor. Drop the stepper motor out of it's housing by pressing it's tab. Unclip the metal rod that connects to it by pushing straight up. Slide the motor housing out of it's track and place aside. Remove second screw for bracket if not accessible earlier. Final stage connector will be visible (5 big gauge wires). Final stage may be screwed in or just clipped in. Remove screws if equipped and push tab on the side toward the firewall. Use the connector wiring still attached to wiggle the final stage out while push tab out of way. Then disconnect connector. Reassemble making sure everything fits and operates correctly as you go. You can find pictures on www.e46fanatics.com (post#8). If you are not a DIY guy then you'll look at $300+ at the dealer. Good luck.
-Evan