complete power loss

[mister1k]

really need some help on this one 92 525i ,a little history I had alternator rebuilt 6 months ago,I have a huge intersate battery good and fully charged.3 weeks ago I get in the bimmer after work I have a 60 mile trip one way.It is minus 30 celsius outside,I have remote starter so i start car 5 minutes before shift end.no problems ,get in car turn on the heat,rear defog etc,start heading home.I go about 30-40 miles,I notice my wipers really running slow,and i swear my lights are getting dimmer,then things start happening,ABS light comes on ,then check engine,then trans program,then tach dies,lights getting dimmer, car starting to run rough.I am lodssing all power all system shutting down systematically,pull off the exprees to a mini mart,theres a cop in the parking lot.Shut the car down before i kill the battery totally,because obviously my alternator doesn't seem to be working.to to start car couple of turns but she is prettywell dead.I ask the cop to call me a tow truck,have a smoke,check my battery connections alternaotr belts,fuses anything i can think of.this was a bout 20 minutes in total. I decide to try and start car one more time see if battery has gained a little recharge.voila Car turns over slowly but has enough to fire up,ALL SYSTEMS GO,everything back to normal.full lights fast wipers no messages,I cancel tow truck,get in car and drive home the last 20 -30 miles,get home shut off car wait 30 seconds and start car no problem.Very puzzled.Next morning throw battery charger on for 4 hours battery fully charged.take off to work daylight now,get about 30-40 miles ,it starts all over again abs light first,check engine,trans program,tach,I gotta get off the highway.I dont have time to piss around I have to get to work,new job cant be late, third day.Brother in law picks me up takes me to work,and has my car towed to BUDDS BMW Oakville,Ontario Canada.They have the car for four days,cost me 1400 dollars for car rentals ,two tail light assemblies ,some dash lights ,and labour and trouble shooting for power loss problem.THEY say Alternator good,battery good,they took car out for two 45 minute runs.Tell me everything checks out.AT NO TIME DURING THE LAST FEW DAYS DOES THE ALTERNATOR LIGHT EVER COME ON WHEN THERE IS POWER LOSS.IT COMES ON NORMAL AT STARTUP THEN GOES OFF. I have car back for five days,no problem,then yesterday on the way home from work exactly same scenario,40 minutes into the drive complete power loss,stuck on side of road,wait 30 minutes for battery to gain little charge,just enough to start car and drive home.everything running again and i can definately hear alternator whine,seems like just not all the time.Anyone have any ideas,are there any modules,i can check,where is General MODULE????????1992 e34 525i 170,000 km,Very strong car.thankx in advance for any ideas or tests I can perform.