Mine blew a fuse i replaced it, but it also burnt the "holder" i had to get anew one from seremotors.
Is the 40 amp the "solid" fuse or the spade one can't remember?
its one of the big ones on the left with the red wires comin out...think its a red one with black stripe...you find out why yours blew?
...think mine has melted the holder slightly