First - my guess IS based on experience (but not with a Samurai, which I don't see as an issue, pretty much every Suzuki built has the headlights wired the same way), and knowing how to read the diagrams.
My point however is this, you don't know me, you don't know my background, you really don't have a clue as to whether or not to take my advice. Given the cost of a replacement switch (if you can find one), the best approach would be to grab a test meter and diagnose the fault, maybe even pay an auto-electrician to wire a "dash switch" to replace the on/off portion of the "combination switch"