auzivision

Following is an excerpt from a memo that is floating around one of the Big three... I believe the source of the data came from their warranty department. I can't verify, but it is worth noting.

We have now had two vehicles come into our department with extensive wiring harness damage. Both of these vehicles had a replacement 15 amp fuse instead of the OEM fuse. The fuse does NOT “pop” causing the wiring harness to catch fire. The fuse has a clear, hard plastic blue body with the amperage stamped into the top there is no white paint on the fuse.

There are no identifying marks on the fuse to tell who is making it. The fuse is distributed by Harbor Freight, I attached a picture of the box of fuses. Your dealers should look out to make sure that suspect wiring problems are not caused by these defective aftermarket fuses.

The 15 amp fuse on this particular truck did not “pop” even at 50 amps. The fuse in the second picture still tests “good” even after a direct short across the battery. We tested six of these fuses and none of them pop.

heinrich

Harbor Freight fuses are cheap and the alloy is so soft to bend and misform and cause possible shorts. I threw mine away after bad experiences.

BTW their zip ties are so weak as to be unusable. Threw those away too.

John Speake

....... made in China !

AO

Scary Stuff!

HF... good for jack stands and some hand tools. The rest is covered in lead-based paint.

Bill51sdr

My experience with HF has been generally very negative. I have never seen so much junk in one place... with the possible exception of a swap meet. Most of their stuff should be considered "one use only". Just about everything there is "made in China".

mj1pate

I have found no complaint with HF metric closed-end wrenches. Indeed, the extra long variety have already come in handy. Floor jacks seem OK and I found a name brand MityVac at a good price at HF. Their heaviest "U.S. General" tool chest is the sturdiest (400Lb) and most cost effective chest that I found, with the exception of Snap-On. Almost regardless of the very reasonable sale price, I would have purchased this unit. I can convey nothing less than total satisfaction since purchasing it and the side unit.

On the other hand, I have discarded some smaller, "precision" HF carpentry tools before first use, as their lack of virtue became apparent under closer inspection.

In general; their forte' seems to be pig-iron appliances. I would avoid anything that your life may depend on.

Mike

Alan

I do find it very hard to believe that any ATC fuse can survive a direct short across the battery (I'd consider this basically impossible) - so as a result I wonder about their test methods...?

However I do agree there are some poor quality fuses out there - I'm sure this does relate to their rating accuracy but certainly also their contact surface materials are not robust enough for high current fuses (for ATC: 25A & 30A) this is a major issue... and I'm sure has led to some of the fuse panel melting incidents on 928's - due to high contact resistance (corrosion/oxidation).

If you do nothing else buy good quality fuses for the 15A-30A fuses to avoid issues.

A box of a hundred fuses for ~$10 is really probably too good of a deal....

However do be aware that even good fuses are not actually designed to blow at the rated value and also have importent temperature & time coefficients that come into play... they are more complicated to test than most realize.

Alan

heinrich

Alan what I saw was that the fusible link bends, lowering its resistance. This causes heat which melts the plastic, which allows the electrodes to be even closer thereby in effect creating tantamount to a 100A or whatever fuse. Which causes the wiring to heat up and its sheathing to burn off, shorting out the wire to the body, causing a direct circuit to the battery, with portentially fatal consequences. I SAW this happen. I stopped it by removing the battery post .... that took too long, and damage was severe.

Alan

A direct short across the battery (with appropriately sized connecting wires...) should be able to source well over 500A for many seconds... this is enough to melt the terminal material - let alone the fuse element...

However I agree there are cases where poorly designed fuses can bend and join the main terminals - eliminating the fusible element from the ciircuit altogether.

Note that reduced resistance actually reduces local heating - but it does increase the current at which the fuse blows (it may however cause excess heating elsewhere if there is a fault - e.g. frying the wiring loom).

These cheap fuses are obviously poorly designed - certainly mechanically (terminal spacing) but also they probably use a poor choice of terminal/plating material and often use a plastic encapsuation material that shirinks significantly as it melts - dragging the terminal together.

I do believe most of these failures start with contact resistance on the fuse terminals (dirt, oxidation & corrosion) melting the fuse encapsulation - and causing the fuse to self destruct... in a closed circuit way (and this heating often damages the fuse-holder too).

In pristine form - before the fuse element ever gets hot enough to melt the plastic at the side terminal posts it will blow.

Fuses damaged like this usually exhibit damage primarily at the teminal sides - not so much in the middle at the fuse element (see above).

However you look at it cheap fuses may end up very expensive...

Alan

JEC_31

Thanks for the heads up, auzivision!

I've heard from some of my auto industry contacts a couple of horror stories about the Chinese manufacturers' disregard of engineering protocols when it comes to making on-the-fly material substitutions for cost or availbility.

In simpler language, they'll make the damn products (fuses?) out of cow**** if it means making their production numbers that week.






Ha, I was going to say the same thing. My cheap HF pipe bender works great, the cheap HF timing lite went right back.

Ispeed

Like Sterling, I have gone to all new fuses as we all should. I have done new relays too.
Cheaper than 928 headaches.

Tampa 928s

Funny this thread is up today!
Went to HF to purchase a fuse for a switch after finding the store empty of fuses I asked the highly qualified sales associate why. His response they were on recall which in english they sent them back due to issues with there ratings and quality.

auzivision

Just FYI in case you haven't heard. I just read another story about someone having trouble using HF fuses. They have been recalled due to potential issues such as fires:

http://www.harborfreight.com/cpi/recalls/fuse_sets.html

Giovanni

Sounds serious "Consumers should IMMEDIATELY STOP USING THESE FUSES, EVEN IF THERE IS NO APPARENT PROBLEM"

heinrich

I wonder how many car fires, including mine.