"Since you have a TFI ignition, you don't have a ballast resistor. The ballast resistor has been replaced by a resistive wire.
The biggest sign your resistive wire is bad is your Bronco will start, but immediately stop as soon as you let go of the key.
Will try to find aother wiring diagram.
Only Duraspark systems had ballast resistors. If you're running a Duraspark ignition system, you need a Duraspark-style coil. Plus a ballast resistor, which should be in place somewhere in the wiring harness between the ignition switch and the ignition coil primary connection. It's red, and has BALLAST RESISTOR in silver lettering printed on it." by sigEp Blue