The way it works is Sins uses the three .dds files to tile on top of the UV mapping applied to a mesh. So assuming your .dds files are correct (i.e. its not corrupted or it was created with the .dds plugin), and your mesh is correct then the likely cause of the problem is not having UV mapping on the mesh.

I haven't done it for a while tbh so others can give you more detailed advice but in essence thats the reciepe for success.

Do your .dds textures have an alpha channel?  If not, perhaps that's why your models don't have textures on them.  From what I understand, an alpha channel gives the texture reflectivity.  Suppose you're looking at a ship at an angle where the sun is directly on the ship, and the side of the ship gleams.  That is a result of the alpha channel.

thanks for all the help! once i found out how to alter the correct channels, it worked correctly!