Big problem plz help

Today i tried to change battery on my 1999 passat 2.8l i positive on negative and negative on positive. I saw some smoke come out from where the A/C fan and air intake is and i also smelled burning rubber. I took of the battery realizing what i did. I put the battery back in this time properly connected but right when i connect the batt the A/C fan starts goin off. The car wont take ignition, i turn it to ignition all lights light up on the guages but it wont take ignition. No clickn nothing. The fan will keep running whether the key is in the car or not. Plz help i also checked the fuses on the driver side panel nothing seems to be blown in fuse box. Plz guys help

You'll need to go through all of your fuses, and check all visible wiring.. you know in what general area the smoke came from, so start looking for obvious signs of wire damage... the worst thing that you could have done is fry one or more computer modules