Bruce & 6600LB7 I just finished installing the prodigy into my 04 d/a followed the prodigy directions for the GMC/CHEVY & the directions on the GM harness which was in the console when I recieved my truck. The harness plugs in under the dash upper left hand side (it will only plug in one way) the other end of the harness gets connected to the brake controller (plug comes with the controller but other end of controller harness needs to be connected to end of GM harness) you just need to connect the GM harness end to the brake controller end either by butt connectors or soldering, the wires are color coded so you can't make a mistake. Fuse (which comes with the GM supplied harness) needs to be added to under hood fuse panel, if not you will not get 12 volts back to the trailer plug. just pop off the black plastic cover under the hood and remove the red plastic dummy fuse in the panel I believe it's listed as #1 (see owners manual). Mounted controller to r/h side of under dash tucked wires under the carpet. All the searches I did on brake controllers the Prodigy seems to be what everyone was raving about it's true top of the line. Clean install & Technolgy all in one controller.