02 gmc 2500HD 2wd to 4wd conversion

[Brandon18]

I am currently in the middle of making my 02 gmc 2500hd 2wd into 4wd. I have already installed a freshly rebuilt 4wd 4l80e with a manual shift NV261 transfer case. Changed the trans crossmember, rear driveshaft and extended the output speed sensor wires. The truck is running and driving just fine but is still only 2wd as I have yet to install a front diff and axles. 
 

My next obstacle is wiring up the front diff actuator. I would like to figure out if I could wire it how it would be from factory so I would have the 4wd light come on in the dash without having a manual toggle switch or a manual cable to engage the front diff. I’m looking for insight to see if anyone has ever done anything like this. And if it is possible, will the computer have to be flashed or anything to make this work? 
 

I am not shy to dive into wiring schematics or make my own harnesses. 
 

Any insight would be much appreciated!

[dna9656]

I have to ask.... Did you check the frame part number for the 2 wheel drive vs. the part number for the 4 X 4 model frame? If they are the same you're good to go, if not... well I don't know.