Originally Posted by bmwjk
Is balast located in the headlight assembly? Is swapping the ballast the best way to check for bad ballast? where is good source for new ballast? Car is a 2005 325xi
Yep they're connected to the bottom of the headlight assembly. Pretty easy removal, only three screws holding it on if I'm not mistaken. But I think switching the bulbs from one headlight to the other would be faster and easier. That way you dont have to take out the whole assembly and you rule out that it isn't a bulb.