Not sure what section to ask this question so if its in the wrong place please move to the appropriate area.
This is my delema,my trans was cyrrently replaced with a rebuilt,since its been reinstalled it doesn't show on the dash board what gear Im shifting in.
Thoughts and input please.

 

I would check the wiring to your neutral safety switch. I had the same thing happen to me. The wiring to my NSS came loose and layed on the front drive shaft. So when I used 4WD the shaft ate through 2 of the wires and I lost PRND.

 

The NSS electrical connection can be a bear to safely remove on these trucks and is often damaged in the process. Those in the know will remove the NSS from the side of the transmission completely, leaving the electrical connection in place rather than risk damage to both the connector on the harness and the NSS itself.

More than likely, they removed the connection and damaged the connector and/or NSS switch.