Harbor Freight Fuses

RedFish said
I've mentioned this before. My brothers job is field failure analysis on anti lock brake processors and more for Bosch. Those components are powered by 30 amp fuses in any application. Through testing they have found little or no consistency fuses.
30 amp fuses will conduct 50+ amps for X milliseconds before opening.
Nature of the beast no matter who made it.

jos51700 said
I agree, every fuse has a blow time, or time of overload prior to failure. Hence: Slow-blow fuses.

This isn't X milliseconds. This is months (well, the total elapsed time of circuit overload was technically infinity since the plastic had melted/burned away and the "fuse" was still going strong) of wire-harness melting and wires arcing.

"No matter who made it"...I disagree.

I am not trying to defend Harbor Freight either. I attached a part of a fuse spec of a UL listed fuse from Littelfuse, a well known fuse manufacturer. It shows that the max time that a fuse operating at 135% of the fuse rating could last until blowing is 600 seconds or 10 minutes. The 20 amp load on the 15 amp fuse would be 133% of the rating. If by chance the fuse took that long to blow along with the previous owner not using the proper sized fuse (10 amps), I could see this issue happening.

Craig