Sounds like a bad CC switch or ground. Carefully pry the switch out of the instrument panel. Disconnect the 5P connector from the switch. Check for continuity between the terminals in each switch position according to the table.
• If the continuity is not specified, replace the illumination bulbs or the switch.
• If OK, install the switch
PM me an email address and I can send you the connector numbering and the table to troubleshoot.
If it is a poor ground, you would have issues with these other features: G501 (located behing left kick panle) - Clock, Cruise control unit, Cruise control main switch, Data link connector (DLC), Front accessory power socket, Interior lights switch, Driver’s multiplex control unit, Navigation display unit, Navigation unit, Power mirror switch, Power sliding door switch