As I am discovering, the possibilities of the models, I keep bumping into massive bugs, like the other bug, I reported (which was resolved).... .__.
However, I tried to make new models for redstone circuits and... it's invisible.
I tried the EXACT SAME model on other blocks, which worked perfectly fine.

I don't think, there is need for a picture of a non-visible block, but I upload the .json file.
My idea to fix this bug would be to be able to switch blocks to opaque-non opaque and choose the texture for the blocks (or multiple)...
Thanks a lot =/