So I am parting my 1989 Mercedes-Benz W124/300E out, and I ran across this box under the back seat and have no clue what it is, what it does, nor what it is for?

Can someone please help me identify its use nd what something like this is actually worth?

It's roughly 10"x6"x2" and weighs 5lbs 14oz. It has 3 wires coming from it. I have included pictures.

Attached Thumbnails