Originally Posted by okyoureabeast

Someone told me awhile what this is and how it is used, but in my travels that information has slipped my mind. Could someone inform me what this is that I am pointing to? In my 85 300D it's located directly on the driver's side of the engine bay towards the front of the car.


Also I'm guessing that the black box below it is the glow plug relay and strip fuse.

Thanks!