:)

Click the juice button in the infobar.

Um... what do you mean by "grid colours are off"? Apart from that, I think this is a much needed mod indeed! :)

Technically those are added in with the entity file, not in-game, but it is possible to manually add them. Takes a fair bit of fiddling around and replacing a few funcs, I might get around to it, but don't hold your breath :)

Good point. Sorry. I think I was getting tired when I wrote that last post.

Mainly, what I was thinking, was about the way tunnels have the 'taps' at each opening for life support and power.
Anyway, thanks for looking. Sorry about being so dumb. I think, I was thinking life support in terms of the free flow of "O2" through the passage way... maybe?

What? Passages already carry power/life support to domes, you just can't have cables coming off them (which is what this is for).

Might I suggest a thought?
Would it be possible to make passages "carry" power. That way they could carry power from one dome to another dome, and allowing you to tap into the power going 'through' the passage, kind of like the "tunnels" do. Maybe carrying Water as well, between domes.
The power would be the only thing you could tap into externally though. Unless maybe at the corners where the passages connect to the domes?

Just an idea. The concept you're working on sounds 'great', and I really hope that you can get it working, because it makes sense that power should be accessible from both sides.

I suspect that it might be running into problems when you replace the electricity grid that's part of the dome. Perhaps if you skip placing the electricity grid for the passage if there is already one present in that cell?

Yeah probably this mod, it's a little odd in how it works.

I'm not certain if it is this mod that's causing issues, or if it's the same in vanilla; but...

I've got three different electricity grids, the edges of the grids are where a passage attaches to the dome, suggesting that adding the passage split the grid.

passages (and other grid construction) uses special rules

This plus construction ignores cables doesn't seem to work as both seem to suggest it should. I would expect that placing a passage, presuming it accepts a cable connection at all points, would replace the tile of cable with the passage, then wire both ends of the cable to the passage.