A-A Engine Questions

@Tony posted:

Hi everyone,

Please help me understand basic functions here. I have a MTH 20-80007B set, with the A-B-B-A  consist.  I'm under the impression that the second engine (the back A unit) should be able to run independently because it's a motorized unit. Is that true?  The front engine runs completely on its own if I unhook it from the others. I get nothing out of the rear engine when it's untethered. If tethered to the front engine I do get headlight/ditch light when I reverse direction. No sound, no power. Smoke functions fine.

I do recognize this may just be my ignorance, although I can't understand why there is no sound, the number boards won't light, And the ditch lights won't blink as they should. Battery?

It's sitting on the track now charging.

Tell me, should both engine units function on their own if untethered?  I've watched a video where this is indeed the case.

Tony

If it has a tether, it doesn't run alone.  The newer PS/3 A-A sets have no tether, and each engine is a complete unit.  Early PS/3 and all of the PS/2 A-A sets were a master/slave configuration.  The slave won't run alone.

@gunrunnerjohn posted:

If it has a tether, it doesn't run alone.  The newer PS/3 A-A sets have no tether, and each engine is a complete unit.  Early PS/3 and all of the PS/2 A-A sets were a master/slave configuration.  The slave won't run alone.

Thank you Gunner!  That's exactly what I needed to know. The video I saw of both engines running independently was a PS-3 unit. 

This explains so much. Now I just need to figure out what's going on with the rear engine number board and ditch lights.

Really grateful for your advice and help.

Tony