Read my post. IF you replaced the switch, AND it's a good switch, it's either something drawing too much current, or one of the connections right at the headlight switch heating up.
I have non stock Hella conversion headlights. I didn't upgrade the bulb wattage but suspected too much of a draw was shutting something down. I have a brand new switch in my car that I am going to install during a break in the action here at work. Tonight (at 3 f-ing am!) I will find out if that was the fix or not. If you ever drive at night, I highly recommend this conversion. The difference is like night and day. (Pun intended)