1989 k1500 LM7 Swap - Front Diff

So I used what seemed to be the prudent combination on my 1989 Z71, namely, LM7 mated to LS based 4l60E, mated to the trucks original transfer case.

On the wiring end of things, we went through the harness pulling out the stuff that wasnt necessary for the LM7 and then loomed the two harness's together.

So the only issue I have, is what tells the front diff to lock in...it appears to be electronically triggered but I dont know where the signal comes from...I have to determine of that is a circut I might have broken some where and no one seems to touch on wiring of that mechanism in the countless write ups I have been through...lol

Anyone have any insight?

How about putting a rocker switch or similar on the dash to lock it on command rather than at the mercy of the electronics?

There is a switch on the transfer case. Once you place it in 4x4 it energizes the circuit for the actuator in the front diff. Pretty simple circuit really.

Okay, This is what I was trying to determine...obviously there is always the option of running a manual switch, but if possible, I want my truck to seem stock...not only for myself, but I have taken the time to make the truck serviceable in that should I try to sell it down the road, even though it is swapped, if there is a problem with something, the new owner wouldn't have to scratch his head, wondering WTH I did to make something work...lol...SO do you know if the switch is a grounding switch or a powered switch? I DON'T think the front diff is engaging right now...but I am kind of in the shakedown portion of my adventure so I could be incorrect or maybe it is slower to actuate than I remember...right now I am waiting on my tuner to get it running right...we originally flashed up a 5.3 profile, BUT I had to change injector sizing and so I am not actually driving it. Anyways, if it is a powered switch, then perhaps I cut out the power to the switch...hmmm...I'll scratch my head on this tonight but thanks for the pointer.

Also, I know there are a TON of write ups for swaps out there, but I plan to do my own write up because I had at least ten questions I couldnt find answers too and had to just trial and error them, so I think I have some good pointers I came up with doing this swap. Anyways, thanks again for the tip