Normal maps only lights up one side, while the other one stays dark with an all directional light source I've already made a post today asking for a bit of help, but it was bad, and I did not provide enough information. 

My problem is that when I use normal maps, despite the fact that I use an all-directional light, it only shines on one side.

And since I can't post more than two images, here's a gif:



Node setup:


If there's anything I can to, that would be of great help!

Thanks in advance.
Try changing Object space to tangent space in the normal map node.

Object Space Normals are likely to cause unexpected shading effects, as they do not support object transformation and mesh deformations, like tangent space normals do.
Most of the time normal maps need to be applied relative to the surface of the mesh, not to the whole object.
(https://knowledge.autodesk.com/support/maya-lt/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/MayaLT/files/Asts-Object-space-world-space-and-tangent-space-htm.html)