Screenshots:
http://imgur.com/a/KivwJ

• Minecraft Version: 1.10.2
• AE2 Version: rv4-alpha-6
• Forge Version: 12.18.2.2122

Probably related to the cables themself being not a full block/not blocking light. Not sure if we can trick the rendering into it, but @shartte should be the one being able to answer it.

Yeah, this will be tricky to do with model based rendering. I'll see what we can do.