Product review (5 stars): Here's why you have to cut the old wires off and actually follow the instructions...
Here's why you have to cut the old wires off and actually follow the instructions:

This is NOT a fuse that blows when too much current is consumed, as most fuses do. This fuse blows on excessive temperature.

The problem that happens is that the original wiring was not crimped properly at the terminals, develops internal resistance, and heats up. When it heats up enough, this thing pops. Replacing the fuse alone does not solve the problem - it will pop again as the old connection heats up. This is why they want you to cut off the old crimp connectors and use what they give you instead.

It's not magic, it's just physics. If you don't follow the instructions that come with the thing, you'll be replacing it again in a while.