New battery and regulator. Leakage test says 3.4. I know what it means but wanted to know what are the most common wires to go or come loose. Also starts sometimes but sometimes it just clicks. Cleaned the wire to the positive wire from battery cause it was green and dirty.

 

Check all ground connections too. If they aren't up to snuff, you won't charge up properly. Check the main bundles of wires in front of the battery. Chafing through could be an issue. Crash damage to lights or dash could also cut a hot lead and drain away battery.