Correct you DO NOT need anything at pin D if you are not towing.
(sorry it appears as pink on my computer). Keep in mind that the abuse of fuse blowing may now have damaged the 4th gear pressure switch. Yes teh fuse is supposed to protect it..but current must be high enough to blow the fuse...unfortunately that current may also be high enough to damage the switch.
You can just cut the wire comming from pin D. When the internals are working correctly, +12 volts at pin A will cause the TCC to lock. This can be done from your manual switch at teh dash or as many people do, via the brake switch and a vacuum switch.