I am completely rewiring a 90 civic for and engine swap and I bought the haynes manual for the integra that the engine came from so I can properly wire the ecu and the engine I came across a symbol that I have been having trouble with and I can't seem to figure out what it is. I can't figure out what the arrow on the side is for.

Any help would be appreciated.

 

The rectangle made of dashed lines means an incomplete or partial view of a component. Looks like just a junction block/ splice pack for a common ground. The arrow indicates another connection... from somewhere. Probably an unrelated item that happens to be grounded in the same place as whatever specific diagram you are reading. I loathe simplified/ incomplete wiring diagrams!

 

Thanks. I figured that's what it was but I wanted to make sure.