Are you saying you have such a harness available? If so how much do you want for it?

Thank you for your help.

What do the harness parts completely consist of? Would they include the plug that goes into the socket at the back of the locomotive, and wiring that is fully and firmly set into the plug?

Thank you very much for your help.

Thank you very much for your thoughtful reply. It is a 4-6-0, in particular the "Pioneer" Atchison Topeka Santa Fe set. Unfortunately in the derailment the wires came out of the plug rather than the plug coming out of the socket. The plug remained in the socket and I had to remove the plug from the socket to examine the situation. The sound module does work. The chuff sound is heard loud and clear from the amplifier in the tender, upon the exposed red and black wires contacting each other. My basic problem is how to, either re-set the wires into the plug, or replace either the plug or the wire-and-plug. I don't know how to reconnect it, and I don't know if it is possible to acquire replacement of just the plug or just the plug-and-wire,  without an expensive replacement of the tender car itself. Any advice would be greatly appreciated.

As a result of a derailment, the double wire from the tender to the locomotive that is the connection for the amplified sound feature pulled itself out of the back of the tiny plug-in jack. I reinserted the wires into the back of the jack and plugged the jack back into the little socket (at the back of the locomotive). No sound. Retried repeatedly, including skinning off the insulation and reinserting the wires repeatedly, but no sound. I'm not an electrician. Are than any suggestions short of purchasing a new locomotive-tender set?