Lionel H16-44 NO SOUND-am I doing something wrong???

That engine is nearly 20 years old. It hopefully it just needs it's boards reseated. You need to take off the body shell to do that.  The battery is just to keep sounds going when track power is cut.

Is the volume control pot turned down?

So there IS a battery?

Where is that volume control pot located?

Thanks!

No, there "can be" a battery, but that is not the same as there is a battery.

Some/many MTH engines need and must have a battery for operation.

To my knowledge, I don't know of a Lionel that absolutely positively must have a battery. They "can" have the user install a battery to keep the sounds powered when running in conventional to bridge moments when power is off to change direction in conventional. More worrying, because they can have a user install one- you the new owner should inspect engines to ensure you don't have a dying leaking one the previous owner put in years ago and forgot about.

The volume pot

https://www.lionelsupport.com/...32250LEGACYH1644.pdf

My guesses what is wrong:

#1 check volume pot

#2 reseat modular cards. Lionel shows the parts breakdown diagram https://www.lionelsupport.com/...4-Diesel-591-6-28837

#3 bad railsounds power board.

#4 bad railsounds  board.

#5 bad speaker

I consider the list somewhat in order of likelihood based on experienced failures. Also, I've seen bad Lionel speakers, but typically they still made sound, just cracked or distorted.

Thanks to all of you who responded.  I opened the hatch and adjusted the pot, nothing.  I then put a battery in and again, nothing.  So, I opened her up.  I mean, I had a pretty good idea of why I have no interest in really fooling with these modern locos, but this is staggering!  You folks who know how to work on these things have all my respect!  Anyway, I am going to sell this loco "as-is."  It runs great and I'm sure someone will like it just for the way it runs or someone will dive in and get the sound working, but it won't be me.  Again, thanks for all the input.

Hope you are all doing well, Allen Drucker

P.S.  Is that aluminum foil factory or did someone stick that in there?

I think the aluminum was added.  Also, you should insulate that battery connector.  If there's a short across the battery connector, it could deal a fatal blow to the RailSounds power supply.  That may be where the sound went if that already happened...

Yes, the battery connector was wrapped plastic when I popped the cover and I wrapped it back up before putting the cover back on.  Thanks.