Starter motor clicks

[Markt68]

Hi Guys, I have a 1.6 Zetec 2011 that when trying to start the starter just clicks twice a second. Battery is fully charged, starter has been removed, stripped, cleaned and bench tested all ok. Earth straps cleaned and an additional one fitted. The starter relay and fuse tested ok. I also jumped 2 teminals on the starter relay and starter turns engine perfectly. With the ignition on and jumping across the relay terminals the car starts and runs fine. Any advice would be great