ford 3000 coil

Can someone tell me if I can get a new coil for my 3000 at Napa parts? I thought I read on here that they do have one that will work. If so anybody know part number. Its a 12 volt and does it require a internal resister or external resister. I may have bought the wrong one before. As I said before I am new to tractor mechanics for sure. Kind going at it blind. Thx guys

Per Massy Ferguson, points do best at 5 amps max. When working your battery voltage is roughly 13.5 volts. Divide that by 5 for 2.7 ohms.
Doesn't matter how you get it, internal or external or both, just get 2.7 ohms in the primary circuit and you are good to go.

NAPA IC7 or IC7SB for 6 volt or 12 volt external resistor required
IC14 or IC14SB for direct 12 volts no resistor required.

Just to be technical, coils do not have internal resistors. The primaries are wound to give approximately 1.5 ohms resistance on 6 volt and 3 ohms on direct 12 volt. Both are one continuous coil winding, there is no added separate resistor in the can.

Wow, there are so many problems with this post that I'm not even going to mention them.

Bottom line. your 3000 gasser left the factor with a 6v coil, and a ball of resistor wire in line with the primary.

If you still have the resistor wire, use the 6v coil mentioned.

If you have rewired it straight with no resistor wire or external resistor, go with the 12v coil mentioned.

The coil I put on the tractor was a ABC509 12V Internally resisted from Steiner. This is what they sold me. Where would the resistor wire be. Maybe I have a 6v system I don't really know. Pretty dumb about these things. Help everyone. The tractor starts fine with the new coil but I don' know if it was converted or not. need all help I can get.

souNdguy - I agree with you that a coil designed for 6 volts should always be called a 6 volt coil, whether it is used in a 6 volt system without any external resistor, or in a 12 volt system with an external resistor, but the manufacturers of the coils have chosen to mark the bodies of some 6 volt coils as "12 volts external resistor required" so lots of folks think that they are in fact 12 volt coils.

I'm not sure why son companies obfuscate and dumb down tech...

Not being a tractor mechanic or any kind of mechanic, how can I tell whether I have a 6 or 12 volt system? I bought this tractor used from a tractor dealer in my area. I know its a stupid question but I build things not a mechanic and know nothing about these things just trying to learn from the pros. Thx

(quoted from post at 06:24:18 07/22/16)
Not being a tractor mechanic or any kind of mechanic, how can I tell whether I have a 6 or 12 volt system? I bought this tractor used from a tractor dealer in my area. I know its a stupid question but I build things not a mechanic and know nothing about these things just trying to learn from the pros. Thx

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The Ford 3000 left the factory with a 12 volt system and I doubt that it was ever converted to 6 volt. Ford tractors made prior to 1965 had a 6 volt system when they left the factory if they had gasoline engines and 12 volt systems if they had a diesel engine, but lots of the older 6 volt tractors have been converted to 12 volts along the way.

The question you need to be asking yourself is which coil you need at this point based on whether there is an external resistance in the coil circuit. Follow the two small wires from the coil. One should go to the distributor. The other one will eventually make its way to the key switch. Follow the one that goes to the key switch along its length. If there is a section of the wire that gets fatter with a heat shrink coating on it then that is the original resistance wire and you should use a coil that is either labelled as a 6 volt coil or as "12 volt external resistor required" (NAPA part number IC7 or IC7SB as rsvirgil_KS said). If the wire connects to a ceramic block that is a few inches long and there is another wire at the other end of the ceramic block that continues on to the key switch, then that is a ballast resistor that was installed because the original resistance wire was removed, and again you should use a coil that is either labelled as a 6 volt coil or as "12 volt external resistor required". If the wire goes all of the way from the coil to the key switch without that fatter section and without the ceramic ballast resistor in line then you should use a coil that is marked "12 volt no external resistor required" (NAPA part number IC14 or IC14SB).

Thanks for the help Sean. I'll check it out. Thanks again.