Update by Original Poster
I’ve been away from trains for a while (Family life and 2 other hobbies.).
See Posts #10 and &11 for where I stood before the hiatus.
Updates
(1) Software test.
(a) I deleted and reloaded the Heavy Steam ULT – Still have “Current Overloaded”.
(b) Then, deleted the Heavy Steam ULT and replaced it with the old Heavy Steam -- Still have “Current Overloaded”. So the software is not the problem.
(2) Hardware test
(a) I bought a new LC-3S (that I needed for an upcoming conversion). I unplugged the old and plugged the new.
(b) Found the product, then checked the “Full Load Current” setting. Default setting was 200mA.
(c) Ran load test. Wheels only spun for PART of one revolution. Got a message that said “O mA”. Checked “Full Load Current”setting. Still at 200mA (default).
(d) Re-ran load test. Wheels did not move. Got “Test Failed.” Checked “Full Load Current” setting. Still at 200mA (default).
(e) Tried to run the loco (turned speed knob). Loco did not move. Got “Current Overload” message. As usual for THIS problem, the headlight and sound functions on the HC-2 still worked. So apparently the LM is not the problem.
As G8B4Life said earlier: QUOTE:
Going straight to overload does kinda indicate that there is a path of low resistance from one motor output to the other motor output external to the motor, or there is a fault with the motor that is causing it to draw much more current than before, triggering the LM's overload because it's expecting no more than 220mA.
END QUOTE
The way that this locomotive overloaded and suddenly stopped while travelling at moderate speed on straight track – and has never run since – tends to support the idea that something broke somewhere, or something tiny and partly conductive shifted where it causes problems.
During all of this the entire loco has been gently flipped over on its back (in a foam cradle) several times, and the loco and the tender shells removed. So anything loose should have fallen out.
I am starting to wonder if this loco is worth all the trouble.
Any other ideas???