https://www.lionelsupport.com/...ents/72-1276-250.pdf

It appears you simply connect the two sound terminals together with a on/off switch to activate the sound.  Hopefully you did no harm by applying voltage to these terminals.

Thank you for the information we already have that sheet which does not state the battery requirements for the sound only. Do you know what batteries are needed for the sound system?

As I read the instruction you don't need any batteries.  Apparently you have the transformer already hooked up to the 2 POWER terminals as shown in diagram above.

I assume you have the push button sound switch?  In which case you connect the switch to the 2 SOUND terminals, press the button and the song plays one time.  If you don't have the push button, briefly touch a piece of wire between the 2 SOUND terminals and the song should also play one time.

We do not have the push button box for sound switch.  What powers the sound system? Does the push button box have batteries?  If so we need to know the size.  

The sound system is powered by the transformer you have hooked up to the 2 POWER terminals.  You just have to activate the sound circuit with a push-button switch connected to the 2 SOUND terminals.

Since your lights and smoke are working, momentarily (say, for 1 second) connect a piece of wire, paper-clip, whatever between the 2 SOUND terminals and I'll bet the song plays. 

We have concluded the sound does not work on the unit, we will be happy with the smoke and lights. Thank you so much for your help. 

chenry posted:

We tried 2 AA batteries but no sound, we also tried 9v battery and it  made noise like a wrong speed record. Any sugestions?

I think the "wrong speed record" was the death rattle when you injected 9V into the sound board logic input!