I had a similar situation when driving with the high beams on one night in my
'91 Carat, the next evening I turned on the lights and they didn't work.  I
had to hold the high beam lever on too, to have some light for the ride home
(everyone in the oncoming traffic lane was really in love with me for doing
this but I had no choice).  I unplugged the switch and somehow it had
overheated and melted the plastic on the back of the switch which cocked the
plug on the switch so it did not make proper contact.  I took a knife and
scraped off the excess plastic from around the prongs and plugged it back in
and it has worked ever since.  I really think the solution to the headlight
switch problem (and also a way to get brighter headlights) would be to install
a headlight relay.  This will take the load off of the switch (which obviously
can't handle it) and put it on the relay (which is made to take the current).
My 2 cents.
Ken Wilford
Van-Again
John 3:16