Yet another wiper question

[brian10048]

Been searching through the board and haven't been able to find anyone with the same problem.
I bench tested my wiper motor and it ran fine, but now when i think about it, I think i might have switched the ground and power, but it still ran.
So I put it in the truck and mount my wiper linkages to it.
Without any ground wires hooked up and only the power, the motor turns a little bit when the key is turned on. When the key is off the motor goes back to where it was with the key off.
Now I tried grounding the ground terminals to my ground that everything else in the cab is hooked to. If i remember correctly there were small sparks when grounding the top terminal, and nothing when grounding the bottom terminal.
I then tried hooking the switch up and I still have nothing when i use the switch.

Any ideas??