I have a 99 gmc sierra 2500 6.5 l diesel without cruise control. I heard the ecm came programmed from the factory even if did not come with it. All that is necessary to get cruise on the truck would be to replace the lever to add the cruise buttons and a fuse in the panel and wire it in under the steering wheel shaft. Can anybody share some wisdom on what i'm wanting to do. Thanks a bunch - tired foot in texas!!!