Can a bad alternator cause all HID's to blow headlights n foglights

 

Yes it sure can. About 2 years ago I was driving home from work and everything in the dash started going really bright and then the headlights went out. I finally got home with the 4 ways going and without headlights. I put a volt meter on the battery and it was charging the system at 18 volts. Basically what had happened was the internal regulator in the alternator went bad and instead of not charging the system, the regulator started overcharging the system. It fried my battery and headlights and that was it. I was lucky it didn't do any other damage to the electrical wiring harness.