Disposable

Any help before I have to leave the truck at the dealer for a few days would be great. 2017 Silverado Dual 7 pin and 4 pin connector Test the 7 pin : 8 volts when grounded to the wiring harness Test the 4 pin : 7-8 volts when grounded to the wiring hardness Test the 7 pin : 8 volts when grounded to the Frame Test the 4 pin : 7-8 volts when grounded to the Frame 7-8 Volts on when testing at the fuse panel under the hood. Grounded to the engine block. Relay seems good, all 4 fuses are good. Other Fuses like lights, radio and wipers all bring back 12v range. I am not sure where to go from here. I don't want to miss a ground wire or something. I did clean and re-attach the ground wire next to the brake controller under the rear of the truck. Thanks,