Try reposting your question in the New Holland / Ford forum (owning & operating). Several resident Ford experts who are frequent posters monitor that forum, and I am sure they will come along and offer suggestions.
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
do you have a service manual? schematics are in there.
otherwise.. you will have many positions that can become hot from the main feed.. otherwise when off.. none of the other connecions should be hot. kinda basic description.. but 1 in.. many outs.
A few questions. Are you installing a new ignition switch because of the battery drain? If so you may want to make sure you check the wires from the starter, alternator and light switch to make sure you do not have any places the insulation has rubbed through or connectors touching and grounding out. They don't cover that one in the manuals.