First thing I would do is open the fuse box and spin all the fuses to ensure good contact. They often times get corroded at their ends. If they all look corroded, spend the time to clean both contacts. Use either WD40 or dielectric grease (both sparingly).
Check your bulbs carefully. Make sure you are using recommended bulbs. Sealed beams are not so critical but all others are. Look for corrosion on the bulbs. Use something to clean them off if necessary such as fine steel wool.
If a dealer isn't close by you can order through this site or go to an auto supply store that carries bulbs that have an OEM rating.
You owners manual will also typically list bulb ratings and specs.
Keep us posted,
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