How do I program a ZW-L

I’d suggest checking out Mike Ragon’s video when he was still with Lionel. Kinda long winded but A LOT of good information. 
https://youtu.be/pN5S7X6y9sM

if I understand what your trying to do I hope this helps. As long as your in command mode and you’ve used the “prg-run” switch to set the A handle ID. Then ensure your back in “run”. If you run in 4- channel mode. And set the ID to say TR 20 then handled A is 20 B is 21 C is 22 and D is 23. This is done automatically when typing TR 20, SET. Then to get voltage you have to actually raise the handle to either full power or you can set it back and it will limit the voltage output of that channel to where the handle is set. And simply turn the red knob and voltage will increase. 

hope this helps. I still very much recommend Mikes video. 

Zachariah thanks for the help. I looked at Mike’s video again and couldn’t find where I was doing anything wrong. And still no power, blue light was blinking, and the trains ran in conventional with the remote.

Time to try something else. We have a second ZW-L which we have planned to use on the second level of the layout. Dragged it out, hooked everything up, and turned it on. No blinking light. Programmed it into Legacy, everything worked.

Followed the rest of the steps, now have power as it should be. Problem is with the first transformer. Will call Lionel next week. 

Merry Christmas.

Interesting indeed, surely Lionel will take good care of you. I am a huge fan of the ZW-L (it is a little pricey). Wish it was able to get the full 720 watts they intended to give it. 

merry Christmas!