how to hook up coil

well i cranked her over for the fist time in a few years and quickly realized that the someone who make a good mess of wires in the engine bay, also disconnected the coil. now i have one wire the runs from a terminal on the side of the coil to the side of the distributer, and also the coil lead, but i thought i was supposed to have power running to the other terminal on the coil from some sort of ballast resistor. i checked a wiring diagram and all it said was there is a white wire running from the fuse block to give power to the coil... isnt there supposed to be a ballast resistor? also should i be looking for a white wire? is a 1968 mgb . thanks!! Kyle

Original, 12 volt coils didn't require a ballast resistor.

WHITE WIRE TO PLUS TERM OF COIL
NEG SIDE GOES TO DIZZY

well there were two white wires and i could not get either of them to give me 12 volts so i just jumped 12v to the coil and it fired, but i believe that it was a constant 12v(not key on) because i left it on the coil for a few min. and the coil got very hot. do i need a switched 12v for the coil so that it only has power when its running? but even then wouldnt the coil get very hot if i left the key on?