with all the above that the charging system is causing your idiot lights to turn in and off intermittently. The X5 electronics is highly sensitive to voltage fluctuation (welcome to 1999 technology).
As posted, having your alternator tested (load tested with a carbon pile tester- image below) will show that the regulator is not functional as designed. As mentioned the brushes wear out internally some where between 80-130K depending on electrical load from stereo, AC, wipers, heated seats, etc. You get the picture.
Bottom line: test, repair, or replace. or wait to be towed off the interstate. Your options, Your life.
__________________
2005 X5 4.8IS
The
Blue ones are always FASTER....
Current Garage:
2005 X5 4.8is
2002 M5 TiSilver
2003 525iT
1998 528i
Former Garage Stable Highlights
2004 325XiT Sport
1973 De Tomaso Pantera, L Model
1970 Dodge Challenger T/A 4 sp Alpine White
1970 Dodge Challenger T/A 4 sp GoManGo Green
1971 Dart Sport, “Dart Light” package
1969 Road Runner 383
1968 Ply Barracuda 340S FB Sea-foam Green