A/C box?

[thrtsxchambers]

My truck has a/c but not all hooked up but have a question. The other trucks I see have a box next to the blower motor with a canister but mine does not. As far as I know the a/c is stock but wondering why mine does not have the same components as others, are different years different, mine is an 83'. The only thing not hookes up is the compressor and hook the lines up, my lines feed through the firewall like others but no box and no hole like others where the box is at. This may sound dumb but I'm not familiar with the a/c setup in these trucks. I borrowed these pics from another post but this is the piece I don't have and wondering why but yet have a/c.