If you are blowing the 40a fuse you have a hard short to ground. First, check all connections for proper polarity. The 40a fuse feeds either your v reg or your start relay. Check very carefully your connections to your battery, start relay and to your starter. This is where I suspect the problem lies. Either get a meter or start the process of elimination by disconnecting your start relay and VR and see if it still blows your fuse. The latter process might require many fuses, and might add to the issues by electrically loading something that isn't supposed to be, so be warned.