Good call, Neal!
Zach

Here are the symptoms: Car running at any speed except idle...all the dash lights except the radio pulsate at varying degrees. Headlights, reverse, sidemarkers, brake lights...same deal. Fuel delivery is affected and when the problem is at it's worst I can feel some hesitation. At idle the problem appears to go away. NOW....for the solution, it WAS the voltage regulator in the alternator. I've been told by several experts including the dealer that this problem was within the wiring harness and would take some intensive troubleshooting to find, and there was no way it could be the voltage regulator. Bzzzzzzzz, wrong. This time I went with my gut feeling and swapped the alternator with a known working one off another of my bmws.
Bingo, problem solved, and just to be double sure, I put the bad alternator in the other car, and sure enough...problem is the same. I know there is at least one other guy on this board with this problem. Just wanted to share the solution.

Neal