If you click the switch several times and the brights eventually come on then the switch might be a suspect. If you can get to it with a good contact cleaner (don't know if this is possible ) like "DeOxit" (no commercial ties, just something I have used on other electronics) you might get it cleaned enough to postpone the problem. If your high beams are run off a relay of any kind or if there have been any headlight mods, check everything from the bulbs on back.