I would bet it's the circuit breaker inside your headlight switch that keeps cycling. Your headlights are not fused, because if the fuse blew while you were doing 60 down a mountain road at night, you'd be completely in the dark. The circuit breaker allows the lights to work to some degree without overheating the wires. Are you using halogen headlights? These draw more current than your headlight circuit was originally designed for. I had this same problem on my '85 Mustang after switching to halogen headlights. After going through 3 headlight switches (they would usually last about a year and a half before the flickering would start up again), I built a relay box to take the current load off my headlight switch. You can buy one from Rocketman's Classic Cougar Innovations http://www.rccinnovations.com/index.php?show=menu-hrk-all or build your own like I did.1967 headlights go on and off by themselves , has anyone had this problem if so what was the cause and solution ?