How to Test the Coil on a Ford 8N | It Still Runs The Ford 8N tractor was the successor to Ford's 2N tractor and was manufactured between 1947 until 1952. Testing the ignition coil can be accomplished using a combination of two methods. On all vehicles, ignition coils amplify the spark so that it can make the jump at the spark plug gap; Ford 8N tractors are no Ignition Coil wiring hookup.. (Ba.. - Yesterday's Tractors wwwerdaystractors›Discussion Forums›Tractors(Just be sure you use the correct coil (6V or 12V) based on what ignition system you are using!) ***** Positive Grounded Battery: - Wire from distributor to coil should be connected to the (+) Positive terminal on the coil. - Wire from ignition switch (switched power) to coil should be attached to the (-) Negative terminal on the coil.