General Starter grind

[Robbie62]

Hi looking for ideas every so often when I turn the key I get a starter motor type grind it doesn’t happen all the time I’ve had a new starter fitted and still does it someone said it could be an earth problem if it is can someone tell me witch earth
Thank you

 

[nikrox]

https://www.fiatforum.com/grande-punto-guides/169204-grande-punto-engine-bay-earthing-points.html