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Jim, I will take your questions in the order you asked them: 1) Is this not a good combination? The answer depends: a) If the Wico was originally for a 6 volt system (as they were unless ballast was added), then IT IS A BAD COMBINATION cuz the coil is drawing more current than it was designed for and the heat can damage the windings and/or insulation, its internal resistor, plus the points will burn up much sooner. b) If the Wico already has a 12 to 6 voltage dropping ballast resistor (original type or one added), then THERES NO PROBLEM. Those Wico distributors already have one small internal resistor, but thats to drop 6 volts down even further for its coil, it has nuttin to do with whether or not its equipped with an added ballast used to drop 12 down to 6 volts. NOTE: Even if the tractor was originally 6 volts, is the Wico the original unmodified unit?? (in which case without any external ballast youre over currenting it) or was it either replaced at some time or had a 12 to 6 ballast added?? (in which case youre fine). Regardless what it had original, Ive seen many that got modified over the years. SUGGESTIONS: First see if your Wico has a ballast (not talking about its small internal one) ORRRRR R if one was added in the series circuit between the ignition switch output and the Wico input? EITHER (an original or added) will reduce its input to 6 as it was designed for. If it has NEITHER, you are overcurrenting the coil and points and ITS NOT A GOOD COMBINATION. If it has no 12/6 ballast, the total ohms measured between its input and case when points are closed is probably around 1.5 ohms or so. If it has a 12/6 ballast already, it would be near twice that in ohms. 2) Is there something that could be done to make the 12 volts compatible?? YESSSSS SS, see the above. Simply add a 12 to 6 volt dropping ballast resistor in the circuit between the ignition switch output and the Wico power input, whether its an original or one you buy at a local tractor or automotive shop. If you buy one (Deere or Tractor Supply or NAPA or Rural King or Central Tractor etc.) its ohms will likely be in the 1 to 2 ohms range and around 20 watts, but to drop 12 to 6, its ohms would be equivalent to the total ohms looking into the Wico to its case, so it functions as a 50/50 voltage divider. If its resistance is the same as the total of the Wico and its in series with it, 6 volts would drop across the external ballast leaving 6 at the Wicos inpuit as it was designed to handle. 3) Is there a 12 volt Wico coil?? Not that I am aware of. You simply added a voltage dropping (12 to 6) ballast resistor for use on 12 volt systems. SUMMARY: If its an original unmodified 6 volt Wico Distributor and you ran it at 12 volts, youre lucky if you havent damaged the coil or internal resistior and the points should burn up quicker. If it has no ballast currently, you can easily add one as original or one in the series ignition circuit between the switches output and the Wico input. Its ohms should be near the same as thaT looking into the Wicos input stud so its a 50/50 voltage divider dropping 6 volts leaving 6 at the Wicos input. Im pretty surre Duane Larson has those exact coil and internal resistance values and could, therefore, guide you to the exact ohms required for a ballast. He may be able to guide you to a source to buy an original type 12/6 ballast also. Sorry, I have no data or specs here, but the info and theory above should enable you to see what you have (DOES IT HAVE A BALLAST RESISTOR OR NOT????? ??) and add any necessary ballast to protect your coil and internal resistor and points. Good Luck to ya n God Bless ya, Sorry I dont have the exact resistance specs. Let us know what you find. Hopefully, Duane can give you the exact ohms values. John T
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