Issue making mod

I'm trying to make a van texture mod myself by editing an existing van mod, which DOES work in game.
So I take it, convert from .TEXTURE to .dds, edit what I want to edit, save as .dds and then rename back to .TEXTURE
However, after I make my edits, my mod doesn't seem to work in game. It detects in the mod list but it simply shows the game default van. Does anybody have an idea that could help me out?
Replies
First of all, this should be in the Help section.
Second of all, do you have the Nvidia Texture Tool Plugins for Photoshop?
Third of all, do you have other mods with the van installed?
Fourth of all, are you sure you are editing the normal van / Overkill van and not the opposite one you don't want?