Ramps 1.4 D8 pin unresponsive

So I swapped my anet over to ramps and the D8 pin is unresponsive it is always on allowing the bed to heat during printer standby. I changed the code to swap the fan to D8 and the bed to D9 and that worked but now the part cooling fan is on all the time until power is removed. I am running the printer off cura through USB.

Nothing is improperly wired all polarity's are correct. What would cause this issue?

EDIT: The heated bed is on a separate Mosfet

Edited 1 time(s). Last edit at 01/27/2017 03:25PM by Travb1999.

replaced the mosfet on the board with this one from frys not heating up at all and seems to be working well. all high amperage controls (bed/ hotend) are controlled via external mosfets so very low amperage on these outputs. If anyone has any input please advise me.