Tuoldo ??? Replace the starter solenoid for a 150 amp one if its not been done anyway, it'll give up soon enough. Dead easy.
You could bridge the terminals with a big screwdriver to try the old one first if you want. Turn the key wait for the start up procedure to end, don't press the start button. Put the screwdriver across the two big nuts and hold firm. If that starts it the solenoids dead.
If its a Tunewno it'll be summat else:sigh