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     MODEL “A” PRIMARY IGNITION

          By Claude Sipe



The primary ignition circuit, as Henry designed it, is not wired the same as most other vehicles with a “points, condenser, coil” system. Henry chose to run a “Hot” wire directly to the coil and then to the ignition switch, and then to the distributor via an armor cable. This system works well and with the armor cable it is difficult to “hot wire” so this makes the vehicle harder to steal. There can be problems with this wiring if you try to add an electrical accessory such as a C.B. radio or maybe an electrical fuel pump and wire it through the ignition so it will go off with the key. Simply put, it will never work right! Depending on what you wire in, you can really get some confusing symptoms. If you have a stock vehicle and want to leave it wired as Henry intended, you can’t make it work right unless you change the wiring. Here’s how to change the stock wiring so you can use the ignition switch to turn off your accessories when you turn off the key. First disconnect the battery, this is a MUST, as we will be splicing wires that are “hot”. Now remove both wires that are on the coil. One goes to the battery and the other goes to the ignition switch. Splice these two wires together. Now cut the armor cable and route the end that goes to the distributor to the side of the coil marked +. Now route the end of the armor cable that goes to the ignition switch to the side of the coil marked -. We have wired the vehicle so the “hot” wire from the battery goes straight to the ignition switch, then to the coil, and then to the distributor. You can now add electrical accessories that will turn off & on with the key by wiring them to the – side of the coil, (where the armor cable comes from the ignition switch) with out causing any problems. Another advantage of changing to this wiring, if the wire between the coil and ignition switch grounds out it will only blow your fuse. With the original wiring it can burn out the coil, and in the worst case the coil can blow up! Just ask Bill Graham, or you may have been at the President’s pot luck in 2009,and were able to witness it happen first hand!

Happy Motoring
Claude Sipe