How do I join two models together without messing up the texture? I have a model of a human body and a human head, and both models use the same texture file. When I go to join them together into one form, however, the head's texture jumps to all bundled in the lower left corner,messing it up. how can I stop this from happening?
Your are using two UV Maps with different names.

When you join the meshes, the UV Maps will be mantained:





If you want to merge the UV Maps, just assign them the same name before merging.