what is this?

i have a 87 ranger with the 2.0, it has been cranking just fine, but yesterday when i turned the key it started to crank then quit, when i tried again it made a buzzing noise and the noise was coming from the area in the picture. the arrow is pointing to the piece i think it is, but i have no clue what none of that is. i was under a black plastic box on the passenger side fender. if anyone can help me out i appreciate it.

I work roadside assistance and have had a few older Ford's that buzzed and many of them I've determined to have a bad starter solenoid. I just jumped the posts and she fires right up.

The starter solenoid is the thing to the left of the arrow with all the wires hanging off of it. That could be something to look into if she's just buzzing and not cranking.

it was the starter solenoid, so after a trip to the parts store 15 bucks and my girlfriend letting me use her mustang to jump the dead battery its cranking better than it did before thanks for the help