attn all wiring/electrical gurus!

[SunshineAcid]

i have been working on a particularly challenging swap, so i need some help from you guys as im getting rather stumped.im going to break this down step by step to make it easily understoodi have two cars1: 1991 240sx coupe automatic2: 1989 240sx fb 5 speedafter climbing under #1 and putting 3 fingers though the rusted frame of car, decided to invest in #2.#2 has blown engine. so we decided to swap the dohc (auto) into the sohc 5 speed chassis.heres the fun part.we pulled the engine bay harness out of the dohc to put into the sohc, but we dont want to cut the engine bar harness at all. we know its good, we know it works, etc. problem: when comparing the F1/m53 connectors (according to the fsm) there are 11 wires. only when we look at the actual harness itself, there are 12 wires. all of them match up, except the very corner, where there is an extra wire. its colors is blue with a black stripe (fsm code: L/B) what is this wire to? where does it go? and why is it not in the FSM for the car in which it was designed?problem 2: when trying to connect this same plug (F1/M53) we have also found that 1: the connectors from the ecu to the main harnesses are flipped 180 degrees and 2 the main harness has about 15 or 16 wires on the sohc harness traveling up into the dash as opposed to the 12 on the dohc. what are these extra wires?how do i complete this?any help whatsoever is greatly appreciated.thanks in advance