What Parts Get Burned When Car Battery is Connected Backwards?

[Brooke]

Consequences and countermeasures for reversing car battery terminals are as follows: 1. For vehicles with ECU-controlled systems, the ECU remains powered continuously. If terminals are reversed, these circuits will be the first to burn out, potentially damaging sensors as well. 2. There are two possible outcomes when circuits burn: either they burn open (circuit breaks) or burn short. If burned open, the damage stops there; if burned short, it will continue damaging other electrical components until a fuse blows. 3. Circuit burnout happens instantaneously - by the time smoke appears, multiple components may already be damaged with unpredictable consequences. 4. Inspection should begin with checking fuses, then battery voltage. After correct battery installation and power-on, observe dashboard displays, test electrical components (lights, horn, alarm, radio, power windows etc.), start the engine to check displays, and test AC system. Any malfunctions require repair, with ECU and sensors being most vulnerable. 5. Battery disconnection causes data loss requiring 4S dealership initialization, commonly called decoding or code matching.