Cruise control will not set

I recently had a Pyle PLPSMR9 Reverse Parking Sensor System installed in my Dodge Ram 1500 conversion van, 33,200 miles and a 5.1 l engine. This includes 4 sensors across the rear bumper and a camera mounted on the rear all running through a control box mounted in the back of the van and into a special rear view mirror. The mirror acts as the monitor for the camera, displays numbers indicating distance from an object and is the speaker for a system of warning beeps.

Problem: I used my cruise control on my way to have the installation done. On the way home pressing the ON/OFF button lit the CRUISE indicator on the dash but pressing the SET button did nothing. Is there anything the installer could have done to cause this? I would appreciate any suggestions.

Thank you
njhoosiers