Headlights start flashing after about 8 minutes

Ok the car has a headlight problem. The main headlight switch was replaced due to a melted connection. I also replaced the plug and repaired the wire. At the time this made sense bad connection as it heats it looses connection and the lights go off. This did not fix it next logical Idea check all fuse connections and follow wiring to the dimmer switch. The connections were tight not corroded and everything intact. Which lead me to believe at this time that it was probably going to be the dimmer switch. So I purchased a dimmer switch and installed it same problem no change. It is acting like a bi metal circuit breaker is heating up breaking the circuit cools off and the lights come back on. A lot like a turn signal relay and the timing is about 10 sec on 10 off after the first 8 minutes. As far as I can tell there is only the 50 amp fuse under the hood and the two low beam 10 amps in the fuse box. What am I missing, the schematics that I had access to were incomplete and and pretty much useless as everything but the headlight circuit was covered. This problem affects both High and low beam lights and considering that there are two separate power feeds one going to the main light switch and the other to the multi function dimmer/turn signal it has to be something common to both. (When the lights first went off my wife pulled the dimmer switch back and held it to get the lights back on but it only worked for a short time before they started flashing again.) I still have voltage at both sides of the 50 amp fuse when the lights go out and come back on. I have not checked amperage but as cleanly as they turn off and on I did not feel that was a problem yet.