What is causing the fuses to blow when you hook up a new starter and turn the key over

was the starter changed for other then a complete failure? Does the starter engage then blow the fuse or does it blow immediately? If the starter is misaligned it could jam on the ring gear and blow a fuse

You probably have the small wire touching ground, when you turn the key, 12V run threw to the solenoid, wire is only live when you turn the key.

what types of the Engine? it's a diesel /petrol? it's conventional/latest engine? if a diesel that has a common rail,the dpf (diesel particulate filter blocks,replace it to a new one.the MIL (Malfunction indicator lamp illuminates on the dash while the engine runs.Erase with the G-SCAN 2.Road test afterward. cheers, Bwebwereiti.

I've put in a new starter motor, a new ignition switch, a new neutral inhibitor switch unit, a new key cut, but still no kick over