Vehicles with air bags require the negative
Battery Cable to be disconnected and isolated for two minutes, so the air bag system capacitor can discharge prior to working on the A/C heater control. Doing this is necessary to avoid air bags going off when they shouldn't, potentially causing harm or death. Keep in mind that ATC A/C-heater controls vary between model years and vehicle lines; thus, only use the control designed for the vehicle at hand. Disconnect the negative cable first from the battery. After that, take out the center bezel from the dash and unplug any wire harness connectors on the A/C-heater control board, setting the center bezel aside on a workbench. After that, unscrew the four screws securing the A/C-heater control to the instrument panel center bezel and remove the A/C-heater control from the bezel.