Was your Rio Grande a factory installed Sound unit? I think that SoundTraxx is making the boards for Athearn without the lights (LED'S) so they can save a few cents.
I just bought a Athearn Genesis sd70 ace Union Pacific my qustion is shouldn't there be red lights on the decoder board I don't see any on, my Rio Grand has them.>Could there be something wroung with the decoder, everything works on it.<