First now solved, but just thought I would post this so others may have some info. My tranny and transfer case was replaced last winter. Both failed as when transfer case went out, it took tranny with it. I knew the transfer case was on borrowed time as it was cracked 2 yrs before when my husband had the truck (don't get me started). I kept it going by making sure I kept the fluid level up. Anyways installed used replacements as I had saved up enough for transfer case, but was not expecting tranny to go with it. Pulled them out of a truck with almost 100,000 mi that a tree fell on. Son installed. He made a few errors (like switching 2 wires, not securing wires well and them getting damaged as a result, linkage not quite right) and still had a couple other issues that I was working on solving as I had time/money as at least it moved. The last 2 issues are late shift and 4wd screwy. The late shift probably wouldn't have been noticed by most, it was only about 500-1000 rpms off- worse number when first starting- but I am very attentive with my truck. Parts were cheap...transmission solenoids. I had him replace those today. Shifted at right rpm's on way home after truck sat for hours. While he was working on that I took out the 4WD selector switch to check that. Solder looks fine, so put it back in. The issue with that is when you put it in auto, it engages but then light will blink and it disengages and gives service 4WD message and does not come out of 4wd (high, low or auto) without shutting off truck and restarting. I took it in to tranny shop and they cleared code, it was something generic. They wanted 600 to take it apart and find issue....umm no. Has not coded since, but still does not come out of 4wd (high, low or auto) without shutting off truck and restarting and not sure if auto is still engaged or not as it has not been slick out since then. I am still not convinced it is NOT the selector switch as this is the original (2002) and I know these can have issues with solder cracking. I did not take the circuit board out to check back for cracks, as I was not sure if it would break it (and I had no other way to auto parts store). I had an actuator go out on old tranny and replaced that once....but that time 4wd would not work at all. Since I can wait to use 4wd until the winter, I have time to figure it out.