I really appreciate this conversation, guys!

I want only one thing - to have a switch to flip to go into 50%/50% (4WD Hi) mode, which would be best on snowy roads when going into 4WD Low is overkill, while leaving it in Auto ToD mode means it is CONSTNATLY (and annoyingly) engaging and disengaging the front wheels.

I figure I can use a light-up switch to indicate that it's in the forced 4WD Hi mode. That means I should go with option 3, but without the multi-position selector.

So circuit-wise, my switch would be put a dummy load on the output to the ToD, correct? Any advice on how exactly to wire it, and what to put on the "alternate" circuit?

Lastly, I may have that extra ToD ECU you are looking for, mbeach. I will PM you.