Follow up: Received the aux. fan and installed it yesterday on my wife's 2005 X5 3.0. As I still had a little doubt that the old fan was bad (i.e. could it not be working because something that controls it is bad?), someone had suggested they plugged in the new fan and ran the a/c on MAX to check it's operation before removing the old unit.

I did this and it indeed validated that the fan was the culprit. It took about 30 to 40 seconds after switching to MAX air before the fan started to run. It ran very fast for about a minute, then slowed down. I presume this is normal operation.

As far as the install goes, I found the link for front bumper cap removal helpful, though since I couldn't see the two little plastic spring tabs that latch the sides tight, it was difficult to get them unsnapped. I did find that a set of plastic panel removal tools that I'd bought awhile back at Harbor Freight were helpful in getting the sides unsnapped and the fog lamp surrounds removed (there are bolts behind these covers.). To gain clearance to remove the fan, I had to remove all bumper fasteners, but did not have to actually remove the bumper. It was still tight enough that I had to remove the grill from the old and new fans to allow them to slip behind the bumper from below and care must be taken not to damage the fins on the condensor. Not a big deal, but just exercise care.

On a funny note, I got everything reassembled and was pulling my ratchet out of a hole in the bumper surrounding the fog lamp and knocked the 10mm socket off the end of the extension. Arghhh! Had to remove/reinstall again. All in all, it took me too long, because I was so cautious (4 hours in all), but saved $500-$600 in labor costs, so I was pleased.

Ron