'93 tercel headlights won't turn off.

Just picked up a '93 tercel and a couple times the headlights won't turn off, they just stay on till you pull the fuses out and let it sit over night then seems to work again for awhile, don't matter if car is running or not the switch does nothing. Looking for help, thx.

Check the relay. Two of the contacts opposite one another should have continuity, the other two should not. Apply battery voltage to the two with continuity and the other pair should now have continuity. When you stop applying the battery voltage, the other pair should instantly resume having no continuity.