I have also seen ECM's get fried on cars when this happens. You just have to start at the battery and work your way in.Egon Spengler: There's something very important I forgot to tell you.
Peter Venkman: What?
Spengler: Don't cross the jumper cables.
Spengler: It would be bad.
Venkman: I'm fuzzy on the whole good/bad thing. What do you mean, "bad"?
Spengler: Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.
Ray Stantz: Total protonic reversal.
Venkman: Right. That's bad. Okay. All right. Important safety tip. Thanks, Egon.
Sorry I really couldn't resist.
OK, so a myriad of things could have happened, there are a lot of variables. If you are really lucky, only the main fuse or even fuse block assembly would need replaced. On the other end of the spectrum, a battery explosion and blown ECU come to mind. However, you did not mention anyone getting hurt, thank god, so we can assume the battery is just fine. The first question is, what kind of battery/vehicle were the jumper cables connected to, and which battery/vehicle was in need of the jump? Was the wolverine dead, or another vehicle? The first thing to do is get a volt meter to test the battery and see where it stands. Next would be checking fuses one by on starting with the main and seeing if any failed in the over-current situation created by crossing the cables.
Did a cursory speed read on this post and my brain got:Brother tried to jump my side by side off. He reversed the cables like a moron. Now it won't do anything. What happened??