Tim,
You posted, "I learned a long time ago how to read and decipher the MPC's with part numbers and descriptions so have always called the 9N-12250 the "Resistor Assembly (Ignition Coil)" as it is listed and never a 'Junction Block".
It appears the MPC information, you posted here, shows 9N-12250-B as Resistor assembly (Ignition Coil). I do not see the part number 9N12250 shown in that page of the MPC. If I search the Dennis Carpenter catalog, which you often promote people to get and use, the 9N12250 is shown as:
Coil Resistor
- replacement type
- no mounting plate
Online searches for 9N12250 turn up the bare resistor, no mounting block, for most results, not the resistor assembly.
Many people now use the online parts catalogs, as they don't have a copy of the MPC. Then there is the reality many of those MPC numbers have been superseded, as was found for the front seal on a PTO shaft being discussed by others and you, the other day. The current part number for the resistor assembly with mounting block is A8NN12250B, using the online NH/Ford (get over it, New Holland bought them) catalog. The Dennis Carpenter catalog uses A8NN numbers for all the resistor and block assemblies, not 9N12250 or 9N12250-B.
My description may not match the MPC description, or your terms. I am trying to describe what the person new to the tractor's issue is seeing and work them through things. I have no issue with you giving MPC part numbers, etc. but often if you would add more info more at the level of a person trying to learn, to explain these things to them, it could help them. Also giving them the current part numbers to look for, rather than telling them they need to get an outdated MPC. By the same token if the resistor is mounted on an insulated block having a third terminal separate from the resistor circuit screws, where several wires are joined for a power connection, why do I need a lecture about it not being a junction block just because a later model has a different part specifically called a junction block. Many other pieces of equipment in this world I have worked on have junction blocks of various types. Sorry but junction block is not a name, or term, specific to just one 9N-part number.
We can go back and forth on these little details forever and help no one. Post the numbers and use the names you want. I acknowledge the info specific to these tractors you have acquired over the years and respect you sharing it. One thing I will say is that if one is working on a tractor that has been converted to 12-volts, help them with their 12-volt problem, not expound on why it should be 6 volts, time for that discussion passed when the conversion was done, unless they are asking for help doing a full restoration to bring it back to original. You will have to tolerate my ignorance and approach. I will continue to describe things as best I can by using common names/terms for the related part numbers, and trying to explain the purpose they serve, when I think it is helping the person understand. It worked training new people on mechanical projects before I retired, and I think it will help here. I am sure I have made, and will make more, mistakes along the way, just as you have and will.
Hope you are doing well health wise.
Best regards
Jim