Jacob Killam

so i just purchased a 2002 GMC Sierra 1500 regular cab long bed with 4WD and the 4WD system doesn't seem to be working. this is along with the obd2 port and the radio. there are no lights on the 4WD selector switch panel and there is no service light on the dash. I wanted to look at it through a scan tool but the obd2 port would not power my scanner. I checked the fuse panel in the engine bay and in the cab and I could not find a blown fuse but I may have overlooked it. any help would be great because this is the first American car I've ever owned. along with the 4WD not working the obd2 port will not power a device, the radio does not turn on (but the backlighting is working) and the ABS light is on on the dash. I'm not sure how much of that is relevant but I figured I'd just throw it in just in case.