The alert sound is beeping but nothing is lighting up on the dashboard.

Hello, Since the vehicle is sounding a warning, it is very likely that the vehicle will not detect a fault. It likely thinks it is alerting you to some situation. Start by checking the things that cause the alarm to engage: -Headlights off? -Seatbelts buckled? -Does the interior light go off when the door is closed? -Do all of your warning lights display when you turn the key to 'ON' with the engine off? You may have a bad switch for the door, headlight switch/relay, body control module, or a number of other afflictions. You can see if something is maintaining power with the engine off if a fuse has power all the time, though it should turn off with the key. If you have a blank warning light when the key is turned to 'ON', engine off, look closely to see what that symbol is, and track the issue backwards from there. If the body control module is faulty, you will need to test to identify the issue, but this will be difficult because all circuits may test good. Consider using a professional on this one. It will be a tricky diagnosis.