No sound

Not sure, but do you have it programmed correctly ?

I'm kind of in the same boat and want to share a similar experience....I hope, like you, someone can help. I have four Legacy seperate loops.  On my outside loop my steam engines are not producing sound.  The engines work fine smoke, lights, and movement all normal just no sound. The sound does not come out of my 2020 version Reading T1.  I tried my new 10 wheeler on the "problem" loop and same result. Nothing out of the tender. But I have an new Lionel Legacy diesel S2 on a siding of this loop and it works fine.  I moved the diesel out onto the main line and it ran and functioned fine. Not sure what is going on. Why the steam engines dont work but the diesel does.  I also put the steam tender on the loop by itself and it does make sound. Any trouble shooting suggestions?

For starters, do you have sufficient voltage running in that loop for Legacy operation - 18v ?

Yes

Both of these could easily be RF signal problems.  The handrails on Lionel command (TMCC or Legacy) Steam Locomotives are used as the antenna to pick up the RF signal transmitted by the command base.  On command diesels there is a larger sheet of metal glued to the inside of the plastic shell for this purpose.  Being slightly larger in area antennas on the diesels are likely to be a little more sensitive, thus better able to pick up the command signal.

You'll need to check your connection from the command base to the track to make sure that it is electrically sound, all the way to an outside rail on your layout.   Next, make sure that the same outside rail is electrically continuous all the way around the layout (no breaks).  Lastly you'll need to ensure that your command base is plugged into a properly grounded electrical wall outlet.  Without the electric ground pin on the wall wart plugged into the wall correctly you will get a weak RF signal.  (You may need an electrician to check this last part).

You probably don't need to check the antenna connections inside your locos since you have more than one of them doing the same thing.

Mike

All connections are solid. The diesel runs and the lights work in legacy no sound.

Uncle Milty if this diesel is in fact a Legacy engine maybe check the volume controls on your Legacy Remote. If the engine does not have Legacy try setting the remote to TMCC. If you look in the manual for instructions on doing a engine reset that may take care of the problem.

I wanted to follow up on this topic. I changed the location of the Legacy wire today from one section of track to another ( Legacy wire to the rail) and it corrected my issue of my engine working(lights and movement) with no sound. Engines are working fine now on that loop. Thank you to everyone for input.

Sorry for the delay in responding to everyone I managed to take a header and it took a while for my body to regroup.  Following earlier advice the engine's sound has returned, Thank you everyone.