Melted inline fuse

[Craig Burriss]

I had an in-line fuse on the power wire for my electric water pump. It’s a 20amp mini blade fuse that came with the pump and it’s in a weather resistant fuse holder.
Somehow, one of the blade legs burned off, but the actual fuse part of the fuse didn’t blow. How would this even happen?
The wires are in loom and are in perfect shape. I just don’t see why the fuse didn’t blow but the whole thing melted. I cut the fuse out and hotwired it to get home.
My engine got to 260° because of it but seems to be ok

 

[Syleng1]

Cheap fuse got corroded? Some of the fuses made in chy-na seem to disappear with the slightest moisture. Aluminum (what the tabs are made of) gets all powdery and why the fuse it’self did not pop? Who knows. But I’d put an amp gauge on the wire and see if the pump or the wire is at fault.

 

[Dana67Dart]

Melting comes from heat.
Heat comes from resistance.
Doesn't take a lot of resistance it create that much heat.

Best guess is the tab was loose in the holder, or as others have said corrosion.

Same issue with bulkhead connectors and headlight connectors

 

[67Dart273]

Yeh bad connection could be in the fuse or at the terminals/ wire terminals.

 

[RedFish]

I would guess a loose fitting teminal in the holder also. Neighbor had one at a/c fuse in the factory fuse box of chevy pickup. Never melted but one could wiggle that fuse and cause a/c to start and stop.

 

[340six]

There are videos of fuses made in China that go way past what rated at compared to the ones made here. And also fake ones too. Yes counterfeit fuses. Sad very sad.