| Has me baffled, if it was any of the heavy duty starter wiring then brif=dging it out or running seperate feed and earth to pull the solinoid in wouldn't work, but as you say both those test work OK thn it can't be the starter cables. And as feeding the Starter solinoid with seperate 12V and Earth works then it cant be the solinoid.
May be its a poor earth connection to the ECU
The starter button Earths pin 28 on the ECU Body connector (Red/Orange Wire) and if all interlocks (Neutral/Clutch/Sidestand) are correct it then earths the starter solinoid via Pin 1 of the ECU body connector (Red/Black wire)
Checkout the Desmo Due Paddock on Facebook |