New Gauges - No Cruise Control

My speedometer on my 1990 GMC Vandura 2500 conversion van  recently stopped working. I had the mechanic put in a new set of gauges from a Junk Yard 1990 GMC Vandura 2500. When he checked the original gauges he said the speed sensor was working ok so it had to be the gauges. The gauges now work but I lost my cruise control. I am not sure whether this is related to the gauge install or not but I checked the fuse for the Cruise Control and it is ok. Just where is the module located on this van and is there an electrical connection to the speedometer/gauges that may have been left un-connected which could affect the cruise control?

Do you know if it is an electric speedo for mechanical?  For some reason I am thinking it is still a mechanical (cable) driven speedometer but I can;t remember.  If it is mechanical, swap the pickup/buffer from the old speedo and put it on the new.