A/C Switch Circuits
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 Hyundai XG350, 2003 Hyundai Tiburon, 2003 Hyundai Sonata, 2003 Hyundai Santa Fe, and 2003 Hyundai Elantra. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect ECM harness connector. Turn ignition and A/C switches to ON position. Using a DVOM, check voltage to A/C switch at ECM connector terminals. If battery voltage is present, circuit is okay. If battery voltage is not present, repair affected circuit and retest.