I have been an automotive, farm equipment and small engine technician most of my life. In that time, I cannot recall how many times I have chased electrical problems caused by a cheap junk fuse. Online no-name bulk electrical fuses are garbage.
My advice is to use only quality fuses such a BUSS or Littlefuse from a parts store when replacing them. Cheap bulk pack fuses sucker you in with the pricing, but the quality is unregulated. Many of the cheap fuses will melt the plastic but never blow out the center element.
Ideally a circuit fuse is rated to constantly carry about 50% of the amperage number stamped on the fuse. Example: A 20 Amp fuse should handle 10-12 Amps without issue. It can even handle gradual surges close to the advertised rating on the fuse. But a constant 20 Amps will overheat the fuse and pop the center element as it is designed to do.
Just as a controlled experiment, I conducted some 20 Amp fuse load testing on a series of name brand and then a series of generic cheap fuses.
A meter and Amp clamp were used along with a 12V car battery and an adjustable rheostat that could withstand up to 35 Amp constant loads. A (new) riding mower PTO clutch was used as the circuit load. Ample cool down time of 15 minutes was given between each brief load test. Five tests for each were conducted.
The name brand 20A fuses worked as designed without fault, most would pop at or just below 20 Amps. However, the generic 20A fuse were all over the place. Some would fail at 15 Amps while other climbed close to 25 Amps before failing.
In the past I thought I was saving money on fuses, but the problems cheap ones created cost me much more in money, lost time and aggravation.
Hope this helps someone out there.
#2
ILENGINE
The ones that irritate me are the ones where you go to pull them out the plastic comes off leaving the entire metal fuse body in the holder
Better yet are the ones that come in with a piece of heavy wire shoved down in the melted fuse holder and burnt pins. I've had a couple that smoked the wiring harness that way. One was a newer mower, and the customer was screaming for warranty to cover it.
I don't do factory or aftermarket warranty anymore.... It did not hurt me to lose the headaches.
I sent that customer to the dealer, and they even refused him after they had seen the damages.
I typically use mostly parts store Buss fuses these days.
I've even been known to also collect a handful of fuses and relays (for restocking) whenever I visit to auto wrecking yards. Most of the sales guys there just smile a waive me on through because I was honest enough to show them what I had.
I've also gotten a few quarts of new oil and tranny fluid (found in vehicles) that way over the years. At worse they might only charge me a couple of dollars just to say they made a sale.
Auto manufacturers use good quality fuses and relays that last, so I also consider salvage yards a valid (economical) resource.
