2000 Chevrolet Silverado Z71 1500 5.3, 4WD not engaging

This 2000 Silverado came into the shop with several issues.  The primary customer concern was the 4WD was inoperative.  A used transfer case had been installed in the vehicle within the past year.  The "Service 4WD" message was flashing in the Message Center in the dash. 

I started by hooking up the diagnostic machine and seeing what, if any codes were present. Sure enough a DTC (Diagnostic Trouble Code) C0323 was stored.  This code deals with a problem with the transfer case circuit.

Next, I checked the ATC 20 Amp fuse in the engine junction box.  This fuse is "Hot at all times".  It checked good.

Next step was to crawl under the truck, remove the transfer case shield, and have a look at the wiring and the connector.  I was going to check the orange wire on the circuit, which should have constant voltage on it to the Encoder Motor on the transfer case.  When I unplugged the connector though, I spotted a broken wire.  You can see the broken wire (tan wire) to the right of the downward hanging connector.



At this point, I soldered the wire back together and taped it up.  I cleaned some dirt from the connector body and applied some dielectrical grease to it.  After it was all back together, I started the truck, put it in neutral and tested the 4WD switch.  The truck would now engage 4WD just like it was suppose to.  I cleared the code and the truck's 4WD issue was repaired.