Posting for a friend :
He has a 2007 3.0 D-4D. While driving yesterday he noticed the battery light come on while driving. The light came off after he crossed 1500RPM, while at a stop or slowing down the light would come on and once he accelerated it would come come off again. He eventually stopped in a parked position and revved the engine a few times and it came off totally. Since then to this morning the light hasn't come back on and the van is starting and working like normal.
Has anyone ever experienced this problem before?