Hello & Welcome,
Have you checked for power at the headlight bulbs?
Do the DRLs work?
What I would do is check for power and ground at the headlight sockets. You should have power (12 volts) there all the time, as shown in the schematic below. If you don't have power it will be time to check the fuses shown in the schematic (at the top).
If you do have power, you will have to have a ground, and that comes through the Headlamp Switch and the Headlamp Relay. Here is the schematic for that part of the system.
Here is the location of the headlamp relay (item 18), which you should hear clicking when you switch the headlights on and off. If the relay is working, along with the dimmer switch (switch that changes between low and hi beam) you should also see the Hi Beam indicator come ON in the dash.
The best way to start is to look for power and ground at the headlights, and then go from there. It may even be possible that the bulbs are just blown out, since they were stuck on for a long while.
Please let me know what you find.
Take Care, Greg A.