Whats this box??

I have a 1987 Bronco 2...2.9L and Recently discovered a panel in the back seat...below the drivers side rear speaker. Upon removing it, I see a box much like a computer module..and the computer for the truck is in behind the pass. side kickpanel...so my questio is this...what is this box for?...what does it control...fuel system?...Im stumped!

My '85 2.8L had that panel, but it was only to hold the jack. Is there a chance that it's not OEM, and may be, like, an amplifier, or something?

Dont think its an amp. Dosent resemble one...

maybe it is for the seat belt to "wind up" into, put your hand on it than pull the seat belt up and down, see if you feel anything:2cents:

That box is for the electronic 4x4. You can hear it click whenever you push the 4x4 button on the dash.