L298N regulated output is greated than 5V
You are making an incorrect assumption, the L298N is an &quot;H&quot; bridge driver for small motors, not a 5V power supply. The 5 volt output is provided by a separate 78L05 regulator on the module.  This regulator cannot supply much power. Take a look at the schematic link given to you by ocrdu. Be sure all the grounds are connected.