Replaced PS high pressure hose, can't turn wheel (97 Suburban)

I have a 97 Suburban, the high pressure hose line on the power steering has been leaking. I removed the old hose, installed a new hose, refilled the pump, and now I can't turn the steering wheel. I tried removing the new hose and nothing is coming out of the pump, when I look down in the pump with a flashlight I don't think it's turning. There appears to be a electrial switch on the back of the pump, is this some low pressure switch? Could this be the problem? How do I bleed the system? Any ideas? thanks