Inspect Rotor

WARNING: This page is about a different car, the 2014 Hyundai Elantra GT and 2013 Hyundai Elantra GT. However, it is still accessible from the selected car via links, so may be relevant.

Check that there is continuity between the slip rings (C).
Check that there is no continuity between the slip rings and the rotor (B) or rotor shaft (A).

Fig 1: Identifying Slip Rings And Rotor/Rotor Shaft
Courtesy of HYUNDAI MOTOR AMERICA
If the rotor fails either continuity check, replace the alternator.