Yes, I replaced originals with a pair of 100W HID 5000k brightness. You don't think it could be the switch or connector?
Relay harness and warning cancellers or no?
Ballasts can be intermittent without them, and for some reason tend to become moreso with age
Also, you sure about that 100w thing???? Typical wattages are 35w and 55w
100w would probably cook your headlights and is likely a fire hazard