honda accord 2 dr. ex

I just got a honda accord from a customer for free,,well it doesnt run,,was
running 6 months ago. The rear brakes come on when applied,,horn
works,,hazards work also,,no head lights no power nothing inside the car.
Im stumped in what the problem is,,please help...im thinking maybe the
factory alarm was tripped or something and cut all power to car,,,i did
notice that under the steering wheel,,there is a little clear box lights
up green and red when i jiggle the wires,,,but not sure what it is,,doesnt
change anything in the car...please help thank u

 

What's the voltage across the battery terminals?

Please give the year of and mileage on this car in future posts.