just had engine replaced in my 96 626. Check battery light came on after I test drove and took it home but went away. thought the battery may have we3akened after sitting at the mechanics for 3 weeks. Shortly after, the battery light came on when the brakes were applied. This problem went away but resurfaces from time to time. Just tonight I was driving and the dash, radio, and headlights went very dim along with the radio fading in and out, the airbag light would come off and on, and the car would not shift gears after hitting highway speeds(reving at about 4000 rpm at 60mph). Most days it runs better than ever but this is very worrisome after dropping 3 G's. Any thoughts?

 

Being as the engine was just replaced, I would bet anything the mechanic left a ground wire loose in the engine compartment. This can cause all these symptoms you described. There are multiple ground points to look for. So I would start there.

 

thanks. that sound simple and hopefuly wont cost anything.