How to make a Lightmap work in FSX?

Hello, i have a Problem. I have Ultimate Traffic 2 for AI Traffic incl. Power Pack. I have a lot of downloaded Repaints from AVSim, Flightsim, Jürgen Baumbusch, Flying Carpet, FAIB etc.

The Daylight Repaints work perfectly. In each texture Folder of the aircraft is a Lightmpa included. But in FSX the lights (cabin lights, logolights, etc.) does not work by night. What can i do?

The Ultimate Traffic Models work perfectly at night. The cabin lights and logo lights shining permanent. This is what i want.

I looked in the Folders of the aircrafts in UT2, and this are the same models i have downloaded (The Fruit Stand, Aardvark, OSP etc.....).

Each downloaded Models from FAIB and UTT works also. There must be saved the lightmap texture in the fsx main Directory. Is this the Goal for the other models? But i tested this, it not worked?

I have downloaded the program DXTBmpReader. In much lightmaps are a Alpha Channel. What is a Alpha Channel? And how i must saved the Lightmaps (as BMP, DDS, DXT5..)?

Can anyone help me step by step how i can do the lightmaps work in fsx?? And can i use one Standard lightmap for each model, or must every repaint have a own Lightmap??

Please help.

Thanks, Chester66