I just recently bought a 93 k2500 w/6.5 td. THe 4wd doesn't work. The transfer case does, It had been rebuilt shortly before I got the truck. I pulled out the transfer case and trans to change a clutch and noticed one of the plugs on the transfer case don't fit. It's a manual shifted, no motor on it or anything. There was two of em on there, one towards the rear and one right beside the shifting arm on the top drivers-ish side. That's the one that doesn't match up, like the sensor is different than the plug. I figured it leads to the 4wd actuator or something. Which would explain why it doesnt work, but all the info I can find on it says its probably a speed sensor. But my speedo works fine. If I could get some info on what it is and where to get the correct one from I'd apreciate it.