Traveling on interstate highway in rain storm, mid morning, windshield wipers on, instrument panel lights and headlights shut off. pulled off highway and set headlight control to all four positions and all lights remained off regardless of control position. shut engine off and restarted. lights came on in all control positions. set to auto function and returned to highway to go home. still raining, windshield wipers on. traveled approximately 20 miles when all lights shut off again. after reaching home, shut engine off. restarted and lights work in all control positions. will retest again with second driver to verify circumstances