Ok, this shouldn't be too difficult for someone that knows a bit about cars. My door was left open with the seatbelt in it and drained my battery almost fully. My alarm still worked and I had lights but when I went to start it, the starter would just turn over but wouldn't fire. I have a portable charger and I accidentally hooked up the positive cable to the negative battery terminal and the negative cable to the positive terminal. It sparked of course because I have done that before and I never thought anything of it and I went to start the car and nothing happened, no lights, no starter, no alarm, nothing. The battery still had some juice in it but I wasn't thinking and I was hoping I just messed the battery up (it was old), so I went and bought a new battery and put it in and still getting nothing. So my car is not getting any electrical power at all from a brand new battery so what could the issue be? Where does the battery connect to exactly? The problem is obviously when I switched the cables and I shorted something, I just don't know what. I think it's a main fuse somewhere but I don't know anything about the electrical system in a car. I just hope its nothing like the computer that I fried or anything expensive. What do you guys think!!

To protect the wiring between large sources of current including the battery and alternator, and the fuse box, they use what are called fusible links. Honda may have some other things I don't know about. The heavy cable from the battery runs to a terminal on a relay called the starter solenoid. The rest of the power to the car comes off that terminal or one near the alternator. Some cars have a large wire that goes directly from the battery to the alternator. Look both places for a bundle of wires with a lump on each near the terminal. If one of the lumps looks burned, or is even burned in 2, you have found the problem. Otherwise they are a bit of a pain to check, needing to follow each wire and check for voltage or continuity. Once you identify an open fusible link, they can be cut out and replaced. The idea is that when something goes wrong, like connecting up cables wrong, it limits the damage done.