Mystery Plugs

[TheeRickestRick]

Hey everyone, I got an 89 last year and have been finding random open plugs that I was hoping yall could help me identify what they're for. The first one is this rigged piece that is located near the battery.

Thanks for the help

 

[TheeRickestRick]

Here are 2 more. First one is passenger side. Second is a junction for the vacuum lines and I noticed 2 were open with no lines.