bmw e36 m3 98 smg

[TRELA]

i have a same stupid problem, when iam driving my car everything is fine, when a came to a complete stop ( stuck in traffic) the electric fan or (a/c fan) the hign temp fan turns on the car goes into error mode,( dropd from 13.8 vlots down to 12 v) ihave changed the water pump, clutch fan, all the hoses, belts, put a new smg pump, new alternator all temp sensors, i dont know what else to do? please help me any one.