This sounds like a broken wire, a bad connection, a bad switch or a bad ignition resistor. The wire that you added from the battery to the coil has bypassed all of this, and possibly the switch. Check each connection, clean it and reinstall it. If the connections do not have "star" type locking washers on them, add them so the connections stay tight. Regular lock washers are not designed for electrical connections, that's the star washer's purpose. If connections aren't the problem, be sure to check each wire as you go, that way if one is broken, you can fix it then. Ignition resistors come in a variety of sizes and shapes, but none of them should look burned or cracked. If you find something in this condition, take it to an auto parts house and they can find a replacement for you. The switch might look ok and still be bad. A common cause of switch failure is a large wad of keys hanging from the switch. Again, a good auto parts store should be able to help by checking the switch. Mark all connections before removing them and be sure to take the key with you so the switch can be operated to test it.
One other thing, be sure to disconnect that wire you added so the battery doesen't get run down and the coil burned up!