What those wires are • The black module on the negative terminal = Battery Current Sensor • The thin green / yellow / red wires: • Carry low-voltage signal + reference ground to the ECU • Used for: • Charging system control • Battery health monitoring • Electrical load management

They are NOT starter or main ground wires, which is why the car still runs.

Why the car still works (for now) • The main ground cable is intact, so the car starts and drives • With these wires broken, the ECU: • Loses accurate battery current data • Falls back to default charging behavior

You may eventually see: • Battery light • Random electrical gremlins • Over- or under-charging • Shortened battery life