Well I pulled it apart again and did some testing, Black/White wire is neutral switch (ground this wire for neutral) and the black wire is the gear position (different resistance for each gear). The approximate resistances for each gear is 1st=85Ω, 2nd=180Ω, 3rd=380Ω, 4th=680Ω, 5th=1200Ω and the nonexistent 6th=2740Ω. I am having the same issue motioned where my indicator shaft has lost the roll pin connection to the shift drum and is free wheeling. I made up a temporary (which may just stay permanent) switch to select 1, 4 or N using a SPDT center off switch and a couple resistors (see hand sketch diagram). With switch down it simulates being in Neutral by grounding the black/white wire, center off position the ECU sees 4th gear through the 680Ω resister to ground and in the up position it parallels the 680Ω & 100Ω resisters to ground (about 87Ω) causing the ECU to see 1st gear. I think I will mostly use the N & 4 positions unless maybe if running around town...