Question on PS 3.0 tether

The wire on top is a extra ground, it should contact the metal tender post.

Make sure the drawbar is fully seated, then put a small piece of vinyl tubing on the exposed post on the tender to help hold the tether on.

try a different drawbar to see if sounds return to normal

Thanks Clem I appreciate the info

MTH makes a tether retainer now, it's FB-0000037.  The only issue is they don't seem to know about it on their own website, but I ordered them and received them from the dealer portal.  I just checked, and they say they're available, so I guess you'd have to call MTH if you're a end user to order them.

Regarding the sound change:  Do you have clickety clack turned on?

I don't know why they even have that feature

The worst part is, Clickety-Clack is turned on when you do a feature or factory reset!

To be more precise, tethers usually mean the wire type harness connected between tender and engine for steam. Also Diesel ABA types.  The connector in the engine can have solder joints crack usually on the outside and this effects motor and some times power.  PS-1 had sam affliction.  Also the wire inside the harness from tender can break. 

You seem to be talking about drawbars.  Some can have the same solder cracking but it would be on one or both sides of the actual drawbar.  So if you change it that was most likely culprit.  But it can also be the harness from the tender or engine that plugs into the drawbar.  Usually it is the engine side which is more restrictive.  Tender has the swivel to keep pressure off tender harness.

Lastly the drawbar connection does need to be complete and firm.  Partial insertion to tender can cause issues.  G

"""The connector in the engine can have solder joints crack usually on the outside and this effects motor and some times power.  PS-1 had the same affliction.  Also the wire inside the harness from tender can break."""

This is the dog that bit me on my MTH Hudson...

Cracked solder joints on the tether connector were causing it to either run away, or run very erratic (jerky motion). A re-solder on the joints and she runs like new now.

I think what happens over time is that tight curves puts additional stress on the tether and connector causing solder stress cracks, or possible open wires in the tether harness itself (even though an engine might be rated okay for 031 curves). I also think that if the tether harness wire is too short from engine to tender, this could be another stress point on the harness.

I never pull on the tether wire to uncouple/couple to the tender, I work the tether via the plug whenever I have to handle it...