Toyota Repair: 94 Corolla dead except battery light, door ajar light and dome light work, jumper cable, fuse box

Question
My son has installed a new radio and subwoofer to his car......that was done a couple of months ago. The subwoofer is huge and draws a lot of power from the system. When the car is parked he has to disconnect the woofer so that it doesn't kill the battery as it stays on even with the ignition off.

Because he's not the brightest bulb int he bunch he has left his woofer connected on several occassions and has come out to a dead battery and needed to be jumped...

this happened on Monday night and a friend of his tried to jump start him initially when they tried to jump the car they reversed the leads, sparks flew and then they corrected the cables.....I think the reversal was momentary from what they described....they then tried to jump the car but it still was completely dead.....nothing no lights no nothing.....I went over to the car on Monday night (my first attempt to get it going) tried to jump it.....interior light would come on battery light and door ajar lights on dash would come on but nothing else......car won't turn over, brake lights don't light up when pedal is depressed, headlights won't turn on, radio doesn't turn on.......

we let the jumper cable sit on the battery for a while to charge battery no difference.....

Answer
Hello, in the fuse box under the hood near the battery look for a 80Amp alternator fuse, it has a clear plastic cover on it, inspect this fuse it is most likely blown, to replace it you will have to remove the fuse box and open the bottom, this fuse is bolted in.