Hi Rob, good news that its all sorted now, thanks to your hard work and help from the forum guys
I don’t know if you’ve considered it, but I’ve found a lot of benefit from disconnecting the switch that auto enabled CDL when in low. It’s simple to do, just diconnecting the plug from the switch.
If you do any heavy towing or off-road, it’s very nice to be able to select low and still have an open CD. It makes the truck so much more maneuverable in low especially if you’re reversing a heavy trailer uphill into a tight driveway or similar...
Cheers !