Prusa Mendel i3 Rework bed troubleshooting

Hey guys

I am currently building a Prusa i3 Rework. I am almost done and I will soon be ready to print. I have to conquer one last hurdle. Wiring the bed. As of now, on the bed, (PCB Heatbed MK2B DUAL POWER) I am using pin 1 as power, and pin 2 as ground. The bed is wired into the RAMPS 1.4 in D8. The issue I am having: As soon as I plug the board in, the bed instantly starts heating and the heat sink for D8 gets extremely hot after about 5 seconds.
Thoughts? Solutions? I am in need of some help.

UPDATE:

I just measured the power on D8. There is 12 volts to it at all times. Before I even connect it to the PC. As soon as I plug the power supply into the wall and power up the board, there is 12 volts to the bed.

I am confused. I need some help.