Replace three transfer case control modules because they keep burning up?

The actuator on the front of the truck has been replaced that doesn't mean that it's good? But it is brand new. The last time I tried the test drive I had removed it and put the old one back in and both of them are functioning properly. I just replaced it just trying to eliminate a problem. But what's happening is the after about 15 minutes into a drive in two wheel drive just going down the highway normal driving not even messing with the four wheel drive you'll start to smell something burning and what it is is the center of the chipboard in transfer case control module it usually burns it up. Then the lights on the button go out and then the fuse blows and all this happens while I'm just driving down the highway and I'm not even trying to put it in four wheel drive. I've replaced the encoder motor brand new it wasn't OEM it was from O'Reilly's same as the controller and I've ordered the switch because on the dash ever placed it it's brand new as well. I'm going to send you a picture of the chipboard where it's damaged and maybe that will help to point me at which wires doing whatever it's doing. But thank you for responding. I've got a new transfer case control module again but I have not plugged it in because I have burned up three of them so something is definitely wrong and have not been able to locate the problem.

It's the same location that's burnt in all three of the transfer case control modules and it burns this up before the fuses blew while I'm driving down the road I'm not even messing with the four wheel drive it's just doing it by itself something's got to be touching somewhere and I don't know which wire because I power probed all of them and there's no way I can replicate the problem unless I'm driving down the highway and that's almost impossible to do I can take more pictures if necessary just tell me what will be helpful this is a 2000 Z71 lm7 5.3 I also have been getting a break and ABS light illuminating on the dash along with the service 4x4 I don't know if there's related or not but that's the problems trucks having.

Thank you for the help and awesome readable wire diagrams but still have the same issue I been leaving 15 amp fuse from under hood fuse box and only plugging fuse in for a short time to Engage or disengage the 4x4 when I need it But I recently Was re Is probing the wires with my Power probe 3 it has a Wireless short finder Still haven't mastered that though lol but I did find that there was oil leaking through the speed sensor at the transfer case front drive shaft I unplugged it and installed a fuse Is the 4x4 did work I had to shift it manually but the fuse didn't blow with the speed sensor unplugged I got another speed sensor plug it in try it out burned up another computer I had cleaned the pig tail with electrical clean. And thought I had finally figured it out Maybe It's a coincidence but I believe it's something with the speed sensor circuit That's short now and causing my transfer case Is module to burn up. How to check speed sensor circuit and why would the speed sensor circuit blow the transfer case module would be the questions I have. Thank you

I have the exact same problem in my 2000 Silverado z71. My TCCM keeps burning up and I have an ABS and brake light intermittently, I’ve replaced all the same parts and the module twice. Did you ever figure anything out with that speed sensor circuit?

I have a 2000 Chevy Silverado and I’m having the exact same issue with my transfer case control module burning up, I’ve already replaced it twice. I was wondering if you ever figured anything out with that speed sensor circuit, any help would be greatly appreciated