Another 1999 24v with the no bus message

I've had this truck for many years.  Drove it 5 hours from Houston and use it on the farm only.   Always had the no bus code.  Starts, runs no issues at all.  

At first I looked into it.  Speedometer also wouldn't read.  I replaced the speed sensor and followed the wiring and connections back to the dash.  Now speedometer displays 15mph when not moving..  It does move but never bothered to compare speed to actual.  It does also have a parasitic drain on the batteries if left connected.  Previously I had followed wiring and connections and no change to the no bus.  No other lights or other issues known.  If he batteries are week the it won't start and the 4wd light will illuminate. One of the PCM plugs is missing the locking clip and the connection at the fuse box under the hood is stripped so the bolt won't tighten all the way.  Can't read any codes at the OBD2 port

Decided it give it a go again on fixing the issues and putting it on the road again.  Found this site last week or so.  I've surfed a great deal before asking questions, but I am at that point.  Already more help than any other forums on the subject.  I will begin to work on the WT ground mod.

Last night I put a meter to chase the no bus issue at the OBD2 port.  I checked voltage between pin 3 and 5 (using 5 as ground) 2.46 volts.  I checked voltage between pin 11 and 5 2.43 volts but would jump around ranging from 2.39 to 2.43.   I've read it should be 2.51 and 2.49 which I assume it is pretty hard and fast due to computers.  I also assume voltage draw some where from pcm to points in between...  Where do I go next?