Thanks George, I realize that most Ford cars of that era have a resistance wire, generally the infamous 'pink' wire under the dash. My '72 has a ballast resistor mounted between the voltage regulator and the coil, I assumed it was stock. So it sounds as though I should trigger the relay with the blue wire (shown in the 3-wire bundle) as it enters the ballast resistor as opposed to the ballast resistor's output feeding the coil, ?? Wondering if it might be a bit safer to use the output of the resistor (feeding the coil) to trigger the relay) Again, thank you..