2006 XJ8L with 215k Driver's side (left) low (dipped) beam is significantly less bright than other side with new HID bulbs in both. Is it the ballast? I replace the ballast on the left side and reworked the ground stud behind the right side headlight assembly. Any suggestions on the best HID ballast for a car that is rapidly becoming less valuable than the parts to keep it one the road are appreciated.