Which way round did you connect the wires? Black/red is positive at the pump.
Not sure if a dry pump would seize but i'd say it's possible, never seen inside one but I had a problem like that with my water pump, took the engine apart, when i put it back together the seals inside were buggered and it leaked out the weep hole in the housing, but it was ok before.
Hope it's the pump as it's alot easily sorted than having to dick around finding crappy wiring and fixing it all.