OP:
Just wondering about something as described in your original post.
When you say, the loco "keeps moving", do you mean that it keeps moving at the same speed?
Or... does it slowly decrease in speed, finally stopping on its own?
And... what happens if you hit the "emergency stop" button?
That should cut power to the rails and it should stop immediately (along with everything else).
If you have an engine that "runs on, but speed gradually decreases to 0" AFTER you turn the throttle off, that might indicate that CV4 (deceleration) is set to an abnormally high value. Try setting CV4 to "0"...
The best thing to do when an engine's decoder won't behave is to completely reset it "to the factory specs" (usually CV8 to 8), and "start over"...
When you say, the loco "keeps moving", do you mean that it keeps moving at the same speed?
Same speed that I start with (usually 10/128, quick increase button or throttle usually 5). It gets stuck at that speed and won't respond to anything, not even the emergency stop. I either have to kill power or remove it from the track for it to stop.
I tried resetting it to default multiple times and even re-wired it a couple of time. I will say that out of the 4 F7A-B units this was the only one that had the orange and gray wires reversed as far as wires go. Orange wire is wired to - and gray is wired to + on the motor. Not that it mattered but to check I hooked up reverse and confirmed all it did was reverse the direction of the loco. So at least one mistake was made during assembly and evidently something motor related.
As stated above I gave up and put the decoder in one of the B units. Over the weekend since the body's of the units are the same I took the shell, front coupler and window engineers from the non working F7A and put them on the working B unit body. So now I have 2 working F7A and a broken B. Like I said, I don't know much about motors but willing to give anything a try. I didn't see any loose connections, strays or any wires touching.
Thinking about taking the shell and weathering it for my layout or if possible remove the motor and turn it into rolling stock??? I imagine I would have to get new trucks??? Or can I use the ones on there?