still not right.

When you make changes, it's difficult for any of us to guess what you did

1....ALWAYS figure a way to protect. A great way is to get a large wattage bulb, I use (at times) an old stop/ tail lamp socket, and sometimes a headlamp. With a stop / tail, twist the two wires together and connect to them and to the socket shell. That gives you a high--wattage lamp. Hook that IN SERIES between the ground cable and the battery NEG. That way, if something is shorted, the light will show you there is current, and the lamp will protect against damage

2...With the lamp connected an lit, go round and make sure everything is off, and pull fuses one at a time. If that doesn't work..................

Then start unhooking "stuff" one at a time. Don't discount anything!!!. The starter relay might be defective, shorted, as might be the starter solenoid. You might have a corner of a terminal or a small strand of wire "caught" behind a connection and grounding. Might be a defective alternator, or parts missing in the output insulator.

On a factory setup with ammeter (example) the ammeter terminals might be shorted to ground. Use you head. Think about what's hot, what does not go through a switch or the key.

AND CHECK THE BATTERY WITH A VOLTMETER!!!! There has been cases of batteries reverse charged, that is, the NEG post becomes the POS. You look at the connections. It's "obvious" the battery is hooked correctly. But if reverse charged, it's actually wrong!!!