I just received a used Legacy BNSF DASH 9, 6-28364 engine cataloged in 2010. There was no 9 volt battery installed. After running the engine in conventional, I connected the TMCC to the track and ran the engine with the only noticeable problem of a loud buzz after using AUX 1; 5 and getting the normal PA shutdown message. Turning the transformer off, stopped the buzz. Then I installed a new battery and
repeated the normal TMCC start, run and shutdown. After shutdown, I still got a loud buzz that went away after turning the transformer off. I could still hear a low volume "hum" from the locomotive. The hum did not stop after turning the transformer off and then turning the TMCC Command Base off. Disconnecting the 9 volt battery produced a speaker "squawk.
I then did a controlled test to see what was going on after the locomotive shutdown.
I measured the 9 volt battery at 9.08 Volts and then installed the battery. Then after installing the battery I started the engine in TMCC mode. After moving the engine back and forth a few feet, I did an AUX 1, 5, and the engine shut down with the normal PA announcement. After all engine operating sounds stopped, I could here a very audible buzz from the locomotive. I then turned off the transformer and the buzz stopped. However, I could still here a distinctive low volume "hum" from the 9 volt battery area. I could change the hum volume, using the sound volume control. Turning the sound all the way down made the hum almost impossible to hear. I returned the volume to normal near full up and let the engine sit on the track without any transformer voltage and the TMCC Command base off. I let the engine hum for 15 minutes and then disconnected the battery and that produced a noticeable "squawk" from the speaker and the hum stopped. Checking the 9 volt battery voltage produced a voltage of 8.75 volts.
