Hello,

91 Ford Bronco XLT 5.8

Did something really stupid today. I hooked up my battery cables in reverse for a split second until I pulled the negative cable off, and a crackling sound and puff of nasty smelling smoke came from the an electrical monitoring device (pictured below). My truck started fine after that, but the battery light is now on..

Anyone know what I might have destroyed here?

 

The Green wire that comes off that hot post is a fusible link. Move it around and it might have opened. If you have a test lite check starting at the post then go to where the heat shrink tubing is and just below there see if there is juice on the other side if the link.
The part in the pix is the starter solenoid. The red cable comes from the battery and I suspect the green wire feeds some of the rest of the vehicle. Can you do this?