put your multimeter on DIODE test ... connect RED lead to ECU connector blue/black wire (lower row; second pin from the left on your 1st photo) and BLACK lead to blue/green wire of the sidestand switch connector (should be left pin on upper - male connector on your 2nd photo) ... reading should be around 0.7V ... swap RED and BLACK leads and have a look on multimeter again ... reading should be infinity ...