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Subject: 2n runs fine

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John S    Posted 01-24-2019 at 07:04:01 [URL] [DELETE]        [Reply] [No Email]  
  • 2n runs fine
  • I was asking here last week about my Ford 2n problem of not starting and appreciate all the help you guys gave me. The tractor was running good all summer and fall mowing mostly then began to get hard to start. I began troubleshooting my 2n problem of not starting last week confident I could do it on my own. The tractor is six volts and positive grounded and the wiring matches J-mores diagram. Since it had been years since the last tuneup, I went ahead and began with a tuneup on the front mount distributor and the only new parts I installed were points, spark plugs, a cap, a condensor, a rotor, and the Ecklan points. I went to my nearby Napa dealer and got all the parts as Tim Daley listed in the other post. I bought Champion H12 spark plugs and a new coil. While I was replacing the parts and rebuilding the distributor I had checked my battery voltage and it was at 11 volts. That didn’t seem right so I took my battery to the local O’Reilly’s auto parts store and asked if they could test it. They did test it and said it was bad and wasn’t holding a charge. I had also read to invest in a good brand battery so I had to go to a different store to find a Interstate six volt battery. I installed the distributor after I tested it like Bruce mentioned then put the new battery in and connected it all up. I turned the key switch on and hit the starter pushbutton and the tractor fired up on like the second crank! It ran for a good thirty minutes or longer with no problems of stopping or conking out. The only thing I didn’t do but wasn’t sure if I needed to or how to do it correctly was polarize the generator. I have the original one wire generator and it has an adjustment low to high screw on the back cover so I am pretty sure it is the correct three brush type. There is a round cut out on the back of the dash and it has the Ford name and the letter B on it. I think I can polarize the generator there but not sure. The generator has a thing around it with a long screw going across to a bracket coming off the cylinder head and I just read this is the fan belt tightening mechanism. I saw and read in my 2n service book the fan belt should have about a half inch deflection so I had to tighten it up a bit but other than that, I did nothing else and the tractor is running fine now, even though it has been very cold lately, starts right up and runs perfectly.

    What I was trying to find but couldn't in any Ford books was a good explanation of how the electrical system works and what the purpose and value of each component is supposed to be. I mean, I had read that the front coil has a primary and a secondary winding in it, but could not find what the voltage values are supposed to be or how I can check those. I was also wondering why there is the ballast resistor on the back of dash by the amp gauge and why is it needed, and what is it supposed to be doing. Reading some of other guys messages who say you don't need that resistor and the tractor will run ok without it so why did Ford put one on? Then I was looking at the electrical diagram for the side mount tractors and there is no resistor so how come? I understand there is the ignition system and the charging system but are two different systems. It only seems logical that when starting up you depend on and are using the ignition system then once running the charging system kicks in. Thanks to all who helped and tanks in advance to any further answers to my questions.

    John S

    Bob in KS    Posted 01-24-2019 at 12:13:44 [URL] [DELETE]        [Reply] [Email]  
  • Re: 2n runs fine

  • “I had checked my battery voltage and it was at 11 volts.” That would cause hard to no start

    “What I was trying to find but couldn't in any Ford books was a good explanation of how the electrical system works and what the purpose and value of each component is supposed to be.” Do an internet search for “Kettering Ignition”, “breaker points”, “ignition coil”, “ignition condenser”, “resistor” and other related terms. Also do a search for “Ohm’s Law” as this will help explain the purpose for added resistance.

    The basic theory of operation is the same for all distributor ignition systems. The Ford front mount distributor is unique in it’s design, construction, and mounting of the components.

    Others have explained the front mount ballast resistor. You do not use additional resistor with 6 volts, but would add a resistor if using 6 volt coil in 12 volt conversion.

    “I had read that the front coil has a primary and a secondary winding in it, but could not find what the voltage values are supposed to be or how I can check those.” Can type coils also have a primary and secondary winding in them. Coils are transformers with one side of primary and one side of secondary tied together.

    You can “check” a coil with an ohm meter. Primary on 6 volt coil should be approximately 1 1/2 ohms and direct 12 volt about 3 ohms. Secondary approximately 6500 to 10000 ohms. It is difficult to impossible detect a shorted coil with an ohm meter, but significantly higher resistance readings indicate a defective coil that needs to be replaced. To “test” a coil would require equipment found in a specialized shop. In short, don’t worry about it...if coil works use it, if not replace it.

    The difference between a 6 volt or 12 volt “external resistor required” coils and a direct 12 volt “no external resistor required” coil is in the internal winding. The difference is in the wire used to wind the primary side. There is no added resistor inside the can connected in series with the coil primary.

    “for the side mount tractors and there is no resistor so how come?” Because of the way the coil is designed and constructed.

    Jack - Iowa    Posted 01-24-2019 at 08:07:04 [URL] [DELETE]        [Reply] [Email]  
  • Ballast Resistor
  • Congratulations John!

    The purpose of the ballast resistor is to drop the voltage to the coil. It is constructed of a wire with a high temperature coefficient.

    When cold, the resistor is quite low allowing maximum voltage to the coil for starting purposes.

    It soon warms up which lowers the voltage to the coil and thus reduces the current through it and the heat it must dissipate.

    Some coils are built with internal resistance which in effect does the same thing. Those coils generally are marked: NO RESISTOR REQUIRED or something like INTERNAL RESISTOR.

    If your coil does not have those markings you likely need the ballast resistor to keep the coil from burning up.

    Many years of automobiles were built with a switch section on the starter switch or solenoid which by-passed the ballast resistor for starting. You can do the same thing on your N by holding a quarter across the resistor terminals.

    Hope this helps you.

    My email is open if you have further questions.


    Joihn S    Posted 01-24-2019 at 08:58:37 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Ballast Resistor
  • Thanks Jack. So how do I measure the coil voltage and what is it supposed to be? I've read values of 17,000 volts, 22,000 volts and 40,000 to 60,000 volts. Is there a good chart showing each component and what the specs are? I saw flow chart here but not much help with nothing I wanted.

    John S

    Jack - Iowa    Posted 01-24-2019 at 09:10:09 [URL] [DELETE]        [Reply] [Email]  
  • Re: Ballast Resistor
  • Years ago when I did television service I had a meter with a high voltage probe with which I probably could have measured that voltage. No more!

    I would be surprised if you have the equipment to measure it. There are coil testers which perhaps your auto parts store may have. Would not even count on that. Not sure how reliable they are as coils typically fail when hot.

    You can measure resistance but I don't recommend that either. The voltage in your multimeter may be high enough to produce a nice, shocking spark.

    Best test for most of us is to determine if it works or if replacing cures the problem.

    I cannot tell you what the high voltage value should be. Much lower on these N's than you will find on modern vehicles with electronic ignition.

    I do have a 1958 Ford shop manual which may yield further information when I look at it later today.

    John S    Posted 01-24-2019 at 09:35:54 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Ballast Resistor
  • That is why I want to test the old coil. I'm just one of those that needs to know the why's and how's I guess. From the basic things I replaced, other than the good, new battery, I see only the new coil as perhaps being the source of my problem. I am now thinking if only I replaced the battery and the coil and left the distributor alone, I probably would have fixed the problem. A tuneup won't hurt anything, I'm just curious as to what failed. If it was a bad coil, then how or why does it fail? I have never left the key switch on and I don't know how old the old one was.

    John S

    steveVa    Posted 01-24-2019 at 14:20:28 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Ballast Resistor
  • Put the old coil back on and see if it runs.

    Jack - Iowa    Posted 01-24-2019 at 09:59:29 [URL] [DELETE]        [Reply] [Email]  
  • Re: Ballast Resistor
  • If you know the input resistance of your meter you can possibly buy a resistor to make a voltage divider. Even if you do that, it will not prove much as coils have a tendency to fail when hot and heal when they cool off.

    As to why one fails, most likely a break down of the internal insulation. Due to age and heat.

    It is always recommended to trouble shoot the problem rather than throwing parts at it. Unfortunately in the case of the coil few of us have the equipment to actually test one. So replacement is the best test.

    f    Posted 01-24-2019 at 07:37:00 [URL] [DELETE]        [Reply] [Email]  
  • Re: 2n runs fine
  • Glad you got the old girl running good John. I am still studying that pesky ballast resistor. The "round can" coils have a built in resistor and larger gauge wire so do not need a resistor. The "square can" coils are smaller gauge wire and no internal resistor and insulated with tar. Some applications/vehicles use a square coil with resistor (or two) and some use none. I ran my 9N for a season without the resistor before I was told I needed one. I know for a fact you need all the gaskets in the front mount distributor or they will get packed full of snow LOL.

    Farmer Dan    Posted 01-24-2019 at 07:39:08 [URL] [DELETE]        [Reply] [Email]  
  • Re: 2n runs fine
  • I hate spell check. Here is the long version of my handle.

    Farmer Dan

    1940 Ford 9N "Maude"
    1972 Moto Guzzi Eldorado
    2012 Ford F150XLT, 4x4,Super Cab

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