Other information:
Hyundai Sonata LF 2014-2019 Owners Manual: Automatic Climate Control System
To defog inside windshield
1. Select desired fan speed.
2. Select desired temperature.
3. Press the defroster button ().
4. The outside (fresh) air position will be selected automatically.
If the outside (fresh) air position is not selected automatically, adjust the
corresponding button manually.
...
Hyundai Sonata LF 2014-2019 Service Manual: Head Lamps Repair procedures
Inspection
1.
Check the battery voltage. (Low beam will be on when the battery voltage above 9V.)
2.
Check the fuse and relay.
3.
Check the polarity of ballast. (If the polarity are changed, low beam doesn't lighten)
4.
Check the bulb connector securely.
5.
Visually bulb checking ...