Ok so I been wanting to put a 2speedrear on my truck for a while and well a month ago I was using truck to haul off some cars with a trailer and got back home and noticed fluid on my rear rims. I assumed it was another of the original brake wheel cylinders going out and I took hub apart to find it was axle lube. And then I find that the previous owner obviously changed wheel bearings on it and when doing so over tightened the inner hub nut that pushes bearing into place and stripped the threads on the inside but the last 5-6 thread on the outter end we're fine making it appear to thread on normal. So it's basically scrap now cuz getting the dye and tap slightly smaller to fix it was gonna cost 400plus.

But lucky for me I just picked up a two speed rear with the Dayton style rims from salvage for 200 bucks so I made out good cuz now I don't need new rims cuz my old axle had the widow makers and the tires were getting bad.

Anyway to the questions.... Wiring the two speed up.... I did notice that the two speed truck had a electrical component mid speed cable between dash and tranny. I snagged that along with axle. My truck doesn't have this and assuming cuz I have a single speed rear. What is this called and what's its duty?

Thanks Mike