Only a 'suggestion'... I 'worked' for FORD, but they all did the same thing... SEE if you don't have some kind of 'dimmer-delay' or whatever... when you get out of the vehicle, they stay ON for 'so' long... there should be some kind of 'relay' (IF that is the problem), and it might not have anything to do with the headlight switch...
I suggest, STRONGLY, that you GET a wiring diagram... (not hard- takes a little RESEARCH - I'm NOT going to DO it FOR you!), and then 'check' the components!
If I was your next-door neighbor, I could probably FIND, or Eliminate the problem, in a few minutes! But, LONG-Distance 'diagnostics' are hap-hazard at best! From what YOU say, it sounds like a 'circuit-breaker' as opposed to a 'fuse', which is a GOOD thing... BUT, you still need to find-out why the circuit-breaker is kicking out/off, and correct it... I would hate to have to stop ever ten minutes, or so, to wait for a breaker to 'reset' so I could 'continue' for another ten minutes or so!