No Lights, BUT Others are OK
The most common causes of the issue you describe includes:
- A connector in that circuit which has become disconnected.
- A buildup of road film or corrosion inside of one of the connectors in the wiring harnesses for that circuit.
- A cut or broken wire in the circuit which causes the circuit to be "open."
- Corrosion in the light switch or a relay [IF there is a relay in the circuit].
- Corrosion at a ground connection at the light assemblies, BUT that would usually only disable one of the headlights, not all.
There probably may be some more causes that I can't think of at the moment.
