You've got a short somewhere under the dash. Open it up again, and find any wires that have exposed brass (the metal part of the wire, I can't find a better way to describe it....... well core of the wire I guess)
sorry, back to topic. find any wires that have an exposed core and wrap it in electrical tape. you may have a few wires that aren't attached to anything as well. Just cover the ends of those with elec tape. Hopefully that's all that's goin on, but I'm betting 99% that's the problem