Lionel AA F3's only going same direction?

Program them as the same id, not two separate id's,  that way they run back to back, or give them separate ids and build a train, but change the trailing units direction,  the lion chief app should let them run properly,  I have all 4 ns f unit's and they work fine.  Make sure Bluetooth is on in both units

I can’t give them any ID’s with the app or the universal remote. Once I get my Legacy system back I can hopefully figure that out. Haven’t even really had a chance to use my Legacy system. That broke before I could use it.

They should still run back to back through the app, they don't need an ID for that, just make sure Bluetooth is on and both units

I tried for four hours last night to try and get them to go back to back, they refused to do it, they either tried to tear apart my B unit limb from limb or tried to crush it, but if I put the rear A unit the same direction as the main A unit, all is well with the world, just looks funky. I messed with all the switches, tried setting the rear unit as “one direction only” per the manual through conventional control. It didn’t seem to matter, as soon as I used the universal remote, they would just fight each other again. I suspect the previous owner had them set up as two separate lead units through Legacy, which even when I get my Legacy system back I’ll have no idea how to do since my used Legacy system was dead on arrival, so I have never used Legacy at all. I’m well versed in DCS as I’ve had that system for several years and am fine with that, but the Lionel system is Greek to me. I also have an entire LCS system ready and waiting to get hooked up, but until that Legacy shows back up, it’s just collecting dust. I kept trying to find “factory reset” instructions, but it appears if you don’t have Legacy or TMCC, you’re dead in the water with that as far as I can tell. Seems kinda silly if you get into Legacy engines at this juncture in time. You can get all the units under the sun, you just have no way to get full functionality with them without deep pockets and it’s all used and abused.

Well, just to post an update, I got my Legacy system back today, hooked it up with my AA, ABBA, set on the tracks, and the second the legacy U cable was attached to ground, they were cured of whatever ailed them and were able to run back to back. (Of course, this happened when I still had them facing the same direction, while they were in the hardest part of my layout to access, so they started fighting each other way in back… Had to disconnect the U cable again and run them with the universal remote to bring them back around and correct their positions, then reconnected U cable, and all is well with the world).

I wonder if the second powered A was supposed to be a powered B with a dummy trailing A, and someone switched the shells.

I took it all apart on the day I was going crazy trying to figure it out. It was definitely an A unit from its inception. When they would “fight” they would either both put on their headlight, or put on their reverse light and brake lights at the same time. As soon as a legacy signal hit the tracks, one had a headlight, the other had a reverse light as brake lights. Once I receive the driven B unit I may have the same issue again, but I hope not. As of now I have the super bass B unit. I do find it a little odd the shade of yellow that Lionel chose for these units. The yellow on the engines is much lighter than any previous Lionel or MTH units, but I needed something to pull my MTH Prospectors, and they will do, even if the color is way off.

Search:  Lionel Document 71-2911-250.  Page 21, or 22.   Starts, Advanced Operating Techniques.  There is programming for a unit facing forward, and  a unit facing backward. Multiple, more than two units, there is also programming for a middle unit.

1995 Information.   Even more modern Legacy Control still uses the original TMCC consist, ("Lash-up"), programming.