Thanks Stan,
When I get home this evening, I will look and see about the DCS Loco.
It is the SD-70 from the sets that MTH had out a couple of years ago.
There was BNSF, CTX, Union Pacific, and mine is the BNSF.
Now those sets come with a Dash-9.
All worked perfectly before wiring in the DPDT switch.
However, as you have suggested, I will take it bake to standard configurations (Conventional Only) and (Remote Commander Only), then report back.
Could the 18 gauge barrel pigtails have anything to do with it?
Or could the switch be doing something to the signals?