I'm in the middle of building my printer and I'm stuck on the heated bed. I am following instructions found here http://help.printrbot.com/Guide/Inst...ed+Upgrade/147 and am stuck on step 8. The only black and white wire I have doesn't look like the one in the picture. The one I have has a white cap on one end and a black cap on the other, in the picture there is the white cap, but no black cap. I don't have any wires that look like the picture. Am I missing the right wire or do i have the right one and need to modify it? The heated part won't fit with the caps on the current wire. Help please!