Truck Repair: OD WILL NOT CANCEL FROM SHIFTER BUTTON, mechanical troubleshooting, manual lever

Question
I HAVE A '93 F150, WITH FUEL INJECTED 300CID AND E40D TRAN.  I HAD PROBLEMS WITH HARD OR EARLY SHIFTS WHICH I SOLVED BY ADJUSTING THE "MANUAL LEVER POSITION SENSOR" ON SIDE OF TRANS.  BUT ONE PROBLEM STILL REMAINS.  I CAN'T CANCEL OD WITH BUTTON ON SHIFTER.  I HAVE REMOVED BUTTON AND TESTED CONTINUITY THROUGH CONTACTS AND HAVE VERIFIED THAT THE LED IS GOOD BY MAKING IT LIGHT, AND HAVE FOUND ITS RELATED WIRES TO THE "PCM".  HOWEVER, THIS IS AS FAR AS I UNDERSTAND TO GO.

I HAVE A VERY GOOD BACKGROUND IN ELECTRICAL AND MECHANICAL TROUBLESHOOTING AND REPAIR, BUT NOT IN AN AUTOMOTIVE FIELD.
WHAT THINGS COULD I LOOK FOR AND TEST?

I WOULD VERY MUCH APPRECIATE ANY INFO YOU COULD OFFER.

THANK YOU, MIKE.


Answer
Hi Mike,
You are already further than I have been on that transmission.
But, is there possibly a fuse for that?
At the public library, in the refference section, you can find ass sorts of shop manuals, and one with a troubleshooting chart for that truck would likely be there.
Mitchell transmission books are very good.
Good luck,
Van