My starter motor fuse F15 40amp keeps blowing out

What is your question?

I change the battery,alternator and starter put new fuse (40amp) try to start the car won’t turn over and the fuse blows again,I checked the wires leading to starter alternator and starter and there was no faulty wires or short to ground and alternator makes a noise similar to a flat line sound when try to start the vehicle and only goes off when take the key off ignition

What makes this problem better or worse?

Everytime I put a new fuse

How long has your 2008 Land Rover LR2 had this problem?

Car been dead for almost a month