I have a 2000 sunfire. The lowbeams work fine.When i switch the highbeams on both headlights go out. When the car is first started you can hear a relay click back and fourth a couple times then the service light comes on. Both bulbs are ok and fuses are good. On the harness for the headlights, when lowbeams are on 2 of 3 terminals have power and when i try highbeams 3 of 3 terminals have power.

Any ideas?

Thanks,Adam

I had the same issue with my 2001 Sunfire. It was the DRL relay in the fuse panel, located in the upper left of the dashboard, only accessible when the drivers door is open. Hope this helps.

i had a similar problem....my headlight harness was rotten on the edges by the radiator. I had to cut open the harness and reconnect the corroded wires...you can easily access the harness by removing the cover under the hood that needs to come off in order to take the head light out...