Im thinnin out the harness on my Ej swap gl... What is this? Do I need it?

welp. looks like I cant post a picture till i get home. It's a little orange holder thing it looks like it has a diagram of a diode on it. Three wires lead into it: one is red and light blue, one is green and white, and the other is white and red.

What year and model did the harness come from? 

 

I remember there being a couple diodes on various years, but I don't remember exactly what they're for. Pretty sure you need them. 

Its from a 95 legacy. Sorry I forgot to add that haha