No issues here. I have the headlight kit and the foglight kit. I also have the same kit on an F150 for both headlights and foglights. Also the same kit on an expedition headlight. And the same kit on 2 mustangs both headlights and foglights. Never an issue. Both would not burn out at the same time, ballasts would go separately. I would plug the OEM bulb and make sure your wiring is fine.