Here are some possibilities:
* Wiring issues: The most likely culprit. A broken wire, loose connection, or faulty relay could prevent the low beams from functioning.
* Bulb failure (unlikely): While it's possible both low beam bulbs are burnt out, it's less probable than a wiring problem given the high beams and DRLs are working.
* Switch malfunction: The headlight switch itself could be defective.
* Fuse blown: Check the fuse box for a blown fuse related to the low beam headlights.
* Relay failure: A faulty headlight relay could prevent power from reaching the low beams.
* Previous modification/repair gone wrong: Someone may have attempted a modification to the lighting system that has failed.
You should NOT drive the car at night if the low beams are not working. This is extremely dangerous.
What you should do:
1. Check the fuses: Locate the fuse box (usually under the hood or dashboard) and check the fuses related to the headlights. Replace any blown fuses with the correct amperage.
2. Inspect the bulbs: While less likely, visually inspect the low beam bulbs to see if they're burned out.
3. Check the wiring: If you're comfortable working with car electrical systems, carefully inspect the wiring harness leading to the low beam headlights for any signs of damage, loose connections, or corrosion. This is often challenging without a wiring diagram.
4. Test the headlight switch: See if the switch itself is faulty.
5. Consult a mechanic: If you can't identify the problem, take your Mustang to a qualified mechanic. They have the tools and expertise to diagnose and repair the issue.
In short, having only high beams and DRLs is not standard and points towards a serious electrical fault that needs immediate attention.
