fet vs bipolar transistors...

What is wrong with putting the LED, in series with a current limiting resistor, across the fuse?

When the fuse is intact, the LED will be shorted out and will not light up.

When the fuse blows, a voltage will flow through the LED ad it will light up.

lemming:
What is wrong with putting the LED, in series with a current limiting resistor, across the fuse?

When the fuse is intact, the LED will be shorted out and will not light up.

When the fuse blows, a voltage will flow through the LED ad it will light up.

Because then your LED and resistor replace the fuse and current (albeit reduced) continues flowing into your load.

I personally would have designed the circuit like this: