May want to confirm that the cruise control module is actually plugged in (maybe PO was doing some work and needed to unplug it for some reason and forgot to plug it back in).
Would suggest pulling the error codes.
Other possible causes for the cruise control not working are a faulty brake light switch, or issues with the clock spring / spiral cable.
Cruise control not working
Spiral cable and cruise control question
Cruise Control Only Works When Wheel Turned