Automotive Fuses - Does the brand really matter?

Hello, I'm professor John Kelly and this is the  WeberAuto YouTube channel. Today we are going   to look at the differences in automotive fuses  about two weeks ago I shot a video on the Hioki   milli-ohm meter it's the model RM3548 resistance  meter that can measure very small resistance   values clear down to 100 nano ohms and I told you  in that video that I was going to find some less   than reputable fuses to check and compare those  to the factory fuses that are put in brand new   vehicles here there are some huge differences in  automotive fuses that are available out there and   if you buy a major brand fuse chances are that  you are getting a good high-quality fuse and if   you just buy something off of eBay or Amazon or  any other online retailer that you get a huge   assortment of fuses for next to nothing cost-wise  chances are you are buying a very bad quality   fuse that may not protect the circuit that it is  intended to protect and I'm going to prove that to   you so I've done some experiments I went online I  looked on Amazon and I looked on eBay and I found   all kinds of offerings of some generic brand  fuse that's available so I just ordered a box   of 120 fuses from eBay and this one is labeled AJ  wholesale distributors but this same box the same   plastic box I've seen on eBay and Amazon with  just a different card underneath each one with   a different brand and I believe they're this the  same garbage fuses that are out there and I'm here   to tell you that it's a mistake to buy these it's  a mistake to put them in your car and I'm going   to show you why so I knew that I could buy them  online and I did but then I thought I wonder if   Auto part stores are selling them around here and  then I thought of Harbor Freight of course because   they had a recall on these this type if used back  in 2009 and you can see here on their website they   have a recalls saying they're calling all of these  back and to not use them General Motors before   that recall issued a service alert bulletin to  their service technicians warning them don't use   these fuses from Harbor Freight or anyplace else  only use the original equipment fuses that are   recommended by the manufacturer and if you have  a vehicle with a wire harness that the harness   has got getting really hot or is even melted it  could be that the fuse that's in the fuse block   might be one of these garbage fuses and it's not  opening it's not melting at the proper moment in   time to protect the wire harness from getting  too hot and melting through the insulation and   causing short circuits and even possibility of fires  and so this was dated September of 2007 and I had   forgotten all about that I'd forgotten about the  Harbor Freight fuse recall and all of that until   I started messing around with this milli-ohm meter  here this resistance meter from Hioki and   I wondered can you still get these things so I'm  here to tell you yes these are the same lousy   fuses that I believe were available back then  they're just available someplace else so I drove   around town and I thought well let me check out  Harbor Freight to see if they're selling any type   of fuses maybe they have a different brand maybe  they have a different type of fuse so I go to my   local Harbor Freight store which I usually avoid  that at all costs and went in and looked around   not a single fuse in the entire store that don't  sell fuses not only that they didn't have a single   multimeter for sale either nothing and I was I  was quite surprised because I'm not impressed   with their multimeters either okay so then I  thought well okay let's go to the regular auto   parts stores around here so I went to Advanced  Auto Parts I went to a Reilly Auto Parts I went   to AutoZone, I went to Walmart, my wife went to the  dollar store and looked for me. The dollar store is   still pedaling that lousy oil that they sell  but they didn't have any fuses nobody had these   garbage fuses out of China that you can still  buy online you go online and you can get this   whole box of fuses 120 fuses was less than eight  dollars with shipping 120 fuses for eight bucks   and you would think okay all fuses are the same  this is eight bucks the others are 20 bucks for   40 fuses I'm going to buy this one well they're  not the same so when I went to Advance Auto Parts they sell Littelfuse is the brand name and  that Littelfuses and original equipment   manufacturer or supplier refuses and I bought  this assortment of fuses there are 40 fuses   here along with fuse tester that I didn't need  but I wanted an assortment of fuses this whole   kit here with sales tax was twenty one dollars  and twenty-nine cents so almost three times the   cost of the garbage fuses and so Littelfuse is a  major brand used by automobile manufacturers this   is in a sealed package I have not opened it yet we  are going to open it and compare these Littelfuses   to the other brand fuse that's there then I went  to AutoZone and O'Reilly and Walmart and all of   them either were selling Littelfuse or Bussmann  fuse. Bussmann is now owned by Eaton Corporation   I bought a box of 42 fuses they also make quality  fuses and supply fuses to an original equipment   vehicle manufacturers and this was roughly  the same cost as the package of Littelfuses   with tax it was nineteen dollars and 22 cents  so two dollars less expensive and this is in a   sealed package I haven't opened it yet and we  will compare all three of these views --is now   I believe we have two good high-quality sets of  fuses here from buss Bussmann and from Littelfuse   which is owned by Cooper and then we have the  garbage fuses then I also have and we've had these   here at the shop since 2007 we kept some of those  old fuses that were melting wire harnesses and I   have some of those here also and we'll throw some  of those in as a comparison as well now if you go   to the website for Littelfuse they publish for  the exact fuse that we bought these are ATM mini   fuses they publish a specification sheet here  and the specification sheet gives us the exact   old resistance in milli-ohms which this Milli-ohm  meter will measure it gives us the cold resistance   that each fuse should have at room temperature  approximately which is 24 degrees Celsius plus   or minus 5 degrees so that's anywhere from 68  to 84 degrees Fahrenheit is the temperature that   we're talking about here so we have the milli-ohm  resistance specification for Littelfuse they also   have a sheet that you can download called fuse  ology gives you all kinds of good information   about fuses if you want to learn more about fuses  if you go to the busman website they also have a   datasheet for this set this box of fuses or this  type of fuse with all kinds of good information on   it at what current Willa blow has curved charts  for current versus time in seconds and it also   gives us a table of milli-ohm resistance at room  temperature and this table of Bussmann is very   close to the same as the table for Littelfuse  now there's nothing there's no datasheet at all   on these box of fuse that we have here on both  datasheets for the busman and the Littelfuses   they refer to the Society of Automotive Engineers  standard number J2077 and this standard is titled   miniature blade type electrical fuses and it's  about twelve pages of technical information on   this type of fuse the size how to test it under  what conditions do you test it what temperature   the attest to that how do you run it through all  of the cycles of vibration and humidity and dust   and moisture and at what percentage of the current  marked on the fuse of overcurrent should the fuse   melt at because these fuses they go they blow when  somebody says the fuse blows or pops it physically   melts the little element physically melts and so  there are all kinds of specifications here on this   particular type of fuse and now I'll give you a  little bit of information out of this but I can't   show you the whole thing because it's a   copyrighted document that you have to purchase   if you want to you want to see the whole thing  alright well let's do some comparisons here so I'm   going to open all three of these boxes next and  we're going to compare the milli-ohm resistance   value of a fuse of the same size from each of  these brands of fuses okay we are ready to compare   for different brands of fuses I have the brand I  got from eBay made in China I've got the bus fuses   the Littelfuse and then our old Harbor Freight  fuses from 2007 now the specification for testing   these fuses is supposed to be the temperature at  24 degrees Celsius plus or minus 5 degrees and   you can see we are at 28 two point five degrees  here on our temperature sensor on our resistance   meters so we are well within the temperature  range for testing these okay we're going to   compare four different brands of fuses here I've  got the cheap garbage from China right here is one   the bus fuses the Littelfuses and then our 2007  selection of Harbor Freight fuses that have been   recalled Harbor Freight acknowledged there was a  problem and recall them all so let's start with   a 5 amp fuse, 5 amp fuse is by specification from  the Society of Automotive Engineers for cars sold   in the United States which by the way there's a  different European standard from the International   electo-technical committee the IEC for European  vehicles sold outside the United States alright so   there's a there is a color standard it tells you  for each few size what color the housing should be   and so here is a 5 amp fuse from my eBay fuse  collection here the 5 amp fuse is supposed to   have 17.75 milli-ohms of resistance we have 2.0  - here comes the bus brand fuse 5 amp 16.49 here   comes the Littelfuse seventeen point six three  and are really old Harbor Freight fuse 1.3, 1.31   alright so that's the 5 amp let's do the  same thing for the 10. the 10 is supposed to be   7.42 approximately milli-ohms of resistance  my eBay one is 2.03, the bus   fuse Bussman fuse 7.49, the Littelfuse 7.24 and the old Harbor Freight fuses   1.31 exact same resistance as  the five amp fuse that it that we previously   tested all right now the 15 amp fuse from my eBay  purchase 15 amp fuse is supposed to be 4.58   we have 3.14, the Bussmann 4.85, the Littelfuse 4.76   and the old Harbor Freight fuses 1.31 exactly the same resistance as the 5.   and the 10 okay let's do the 20 amp from the eBay  purchase 20 amp is supposed to be 3.21   milli-ohms I'm getting 1.18, the bus fuse 3.43, the Littelfuse 3.54,   and the Old Harbor Freight fuses 1.01 milli-ohm and it should be 3.2 so   at least that's a little bit different than the  first three fuses of the old Harbor Freight all   right now the 25 we're just about done here we got  to do the 25 in the 30s so here's the 25 for my   eBay purchase 1.03 by the way 25  s are supposed to be 2.36 so here   is the Bussmann fuse 2.49 here  is the Littelfuse 2.59 and then   the old Harbor Freight fuses 0.95   and then the last one the 30 amp fuse in my eBay   purchase 1.05 here's the Bussmann  2.04, oh these are supposed to be   for a 30 amp fuse right around 1.85 the Littelfuse 2.02 and the   old Harbor Freight fuse 0.97 as you can see here  from the resistance table the lower the amperage   rating the higher the milli-ohm resistance  should be and if we look at the measurements   we took here from the bus fuses they match up  very close to the specification the Littelfuse   milli-ohm resistances match up very close but  the fuse kit I bought they are all it looks to   me like there's only three different fuses in a  kit where we tested six different fuses because   three of them have almost identical resistances  at around 1 milli-ohm, two of them are almost at two   milli-ohms apiece and then there's one oddball  at 3.14 none of those matched the resistances   of the spec sheet of the Littelfuse or the bus  fuses they're all too low and if you compared   let's say the 10 amp fuse is supposed to be 7.42  milli-ohms of resistance and it has 2.03   well 22.03 up with  around somewhere between 25 and 30 amps of current   according to the spec sheet here from Littelfuse  so a 10 amp fuse is going to not protect your 10   amp circuit it's more like a 27 amp fuse based on  its resistance now the old Harbor Freight ones or   even worse than the ones that I've tested here  out of this kit from eBay because it looks like   there are only two different fuses in all of those  six that we tested three of them were exactly at   1.31 milli-ohms each the 5 10 and 15 amp and  then the 20 25 and 30 were all almost exactly at   1.0 milli-ohms each so that is so low of resistance  that if you look at our resistance specification   here a 30 amp you should have 1.85 milli-ohms of  resistance the highest resistance we had was 1.31   on these old Harbor Freight fuses so even  though they're the right color they are not the   right resistance value and it's the resistance as  the current goes through it that creates a voltage   drop that creates heat that eventually melts the  little element down inside of the fuse itself a   couple of my co-workers that I've talked to said  well you that that's all fine this milli-ohm   resistance stuff but you really ought to hook it  up to a circuit and see when does it really blow   well in researching what it takes to blow a fuse  there's quite a lot to that and I don't have all   the equipment to do for the higher amperage fuses  but I was able to come up with an experiment to   show you the temperature increase based on the  milli-ohm resistance and the voltage drop across   those fuses so let's get that set up next okay  we're ready to do a test comparing the fuses I   bought from eBay versus the good quality fuse I'm  going to use the Littelfuse brand one for this   experiment and so what I have is a fuse holder  right here it's just a wire harness that will hold   a fuse and I'm going to take the 10 amp fuse from  the kit that I purchased on eBay and plug it into   that fuse holder I'm going to connect a voltmeter  to each of the lit but me to lead to each of the   legs so we can measure the voltage drop across  the fuse and if you read the SAE document on   testing the fuse that is where the voltage drop is  supposed to be done so this voltmeter over here on   the right is the voltage drop across the fuse  this meter right here will be the current going   through this fuse as measured with a current clamp  that I have right here and then this Center meter   is the temperature of this fuse and so I have a  temperature sensor right here and I'm just going   to tape it to the fuse body you can see from my  body touching the fuse or the temperature sensor   element there it heated up we'll let that cool  down here just a moment while I'm discussing the   rest of this I have another temperature sensor  that this meter is monitoring that I have taped   to the wire that the current goes ooh that feeds  that fuse so the fuse holder one of the two wires   on the negative side that's the temperature of the  wire and then this meter here on the far left is   the room temperature so initially here we're  all other than when I touched it with my body   we were all real close to our room temperature  of 84 point a to 85 degrees Fahrenheit okay then   over here behind me I have an old son that 40  and I'm using that just as a variable load to   control current going through the fuse and I have  that connected to a battery down below over here   okay so we're real close on our temperatures so  once again room temperature the wire temperature   at the by the fuse. the fuse temperature the  current going through the fuse and the fuse   voltage drop the last part of the equation will be  my phone I'm going to run this experiment for five   minutes and I'll speed it up so you don't have  to endure all five minutes but let's take a look   at several things one let's see how hot the fuse  itself gets because remember it's the fuse that   has to get hot and melt, that metal in there  has to physically melt open in order for the fuse   to go open so let's see how hot it gets on a 10  amp fuse just running 10 amps of current through   it and then let's look at the wire temperature  at 10 amps and the voltage drop across it at 10   amps now by the way there's a specification that  for a 10 amp fuse you're never supposed to run   10 amps through it the maximum allowed is about  75% of that so seven and a half amps would be the   maximum current in a circuit protected by a 10  amp fuse so if you have a fuse that is blowing   intermittently on a customer vehicle look for  aftermarket equipment that's been added on maybe   they're pulling more current through the fuse  then that circuit was intended to handle okay   so let's turn the load on now we're going to watch  this current right here and once it hits ten amps   then I'm going to start the five-minute timer so  let's start cranking that up here we go five amps   six nine there's ten point five amps I'm going to  start the timer right now five minute countdown so   let's watch and see if a current gets too high  I'll adjust it a little bit notice we have a   twenty three milli volt drop across the fuse at  ten point nine amps and our fuse temperature is   increasing it over 91 degrees 88 degrees on the  wire temperature were 80 84 degrees is the room   temperature now remember this is the less than  reputable no-name brand that I bought off of eBay okay our five minutes are up we are at 107  degrees on the fuse 103 on the wire still   at 84 on the room temperature 24 millivolt  drop almost 25 across the fuse at 10.8 amps   of current now when we turn the current off  the amperage test in the SAE document tells   us that the fuse shall carry 110 percent of its  rating for a minimum of 100 hours it also tells   us that the fuse shall open in not less than  three-quarters of a second and not more than   1,800 seconds or 30 minutes at 135 percent of the  rated current and then it gives us a whole bunch   of other specifications there also so it gives  us the quickest time it should go open and it   gives us the longest time that it should go up  and at this 135 percent rating so this was the   10 amp fuse from the box of uses I bought off  of eBay that are totally out of specification   for their milli-ohm in resistance so now let's  take that fuse out and put in a Littelfuse brand   fuse now we have to wait for this to cool down  just a little bit from the current going through   them from our previous test while that's cooling  down the fuse that we're testing now has a higher   resistance a higher milli-ohm resistance which  is going to have a higher voltage drop across   it our previous fuse only have a twenty four  point six million it I'm going to expect to   see a higher one here because it has a higher  resistance if we look at the measurements from   our milli-ohm resistances the fuse that we just  tested had a two milli-ohm resistance the fuse   we're testing now has a 7.2 million resistance  so that should be three times three and a half   times more so three and a half times 24 that's  around 80 millivolts II approximately we're   cooled down to around 87 degrees that's close  enough because these will get hotter the fuse   needs to have a higher voltage drop to have a  higher heat buildup so we're going to expect   to see this temperature to increase higher than  the 107 that the EBA fuses got up to the wire   temperature was at 103 with to an 11 amps that  shouldn't change any because current is current   the wire itself won't have any more current going  through it the only thing different here is the   fuse resistance was higher which will cause it  to heat up more and eventually it would heat   up enough to melt and open so let's try that  now so here comes the current let's take it up   to our 10 10 amps alright here's our 10 amps of  current we'll start the timer notice already we   are at a 102 millivolt drop versus the 24 that  we had before it's almost a little more than   four times our fuse temperature is climbing  rapidly it's a 95 wire temperatures slowly   increasing room temperature is still the same  let's watch and see what happens we're going to   expect this number to get higher than the 107  of the previous views and this number already   is higher all right we are a little more  than one minute in and we are already at   the same temperature that the previous fuse took  several minutes to get to; we're still climbing okay our five minutes are up on the Littelfuse  and I have to hold the temperature sensor on to   the fuse because my tape has lost its adhesion  with the heat but we're at 120 126 degrees is   what I was seeing there 120 arvo lead to draw  up across the fuse I keep losing my clip here   about a hundred and twenty millivolts over here  ten point seven amps of current 122 degrees of   the fuse hundred and eight degrees of wire  temperature 84 degrees room temperature so   I need to come up with a better way to hold that  temperature sensor on there because that fuse gets   too hot for the tape to adhere so hopefully you  can see from this demonstration that if the fuse   internal resistance is too low the fuse doesn't  get hot it doesn't get as hot as it should and   we're not running enough current through it to  pop the fuse but you can see there was a there   was a temperature difference or a 15 degree  temperature difference just from the one fuse   to the other we were at a hundred and seven on  the eBay fuse in 122 to 126 on the Littelfuse   brand so I highly recommend that if you have  some of these off-brand fuses that you realize   that they may not be up to specification and you  may be putting your vehicle wire harness and even   your lives in danger if there's a short-circuit  somewhere while you are driving that disables some   other type of system that affects your ability to  safely control the vehicle that could affect your   life in the lives of those around you the that  more expensive fuses have gone through rigorous   testing as specified by the SAE documentation  there they meet certain specifications the fuse   housing material is not supposed to melt until a  certain high temperature at all times when that   fuse blows you should still be able to remove the  fuse from the fuse block without it damaging the   fuses around it or the fuse block these fuses the  higher quality fuses the terminals themselves are   tin-plated or over plated or even gold-plated in  some instances which gives it better performance   at high temperatures obviously the hotter the  fuse the easier it will be for that fuse to melt   if you're driving a vehicle in hot temperatures  if there's hot under hood temperatures or hot   temperatures around any fuse block that will  affect the fuses rating how much current it   can handle without melting so it's important to  keep the fuse box covers on those fuses to help   protect them from excessive heat so I've learned  a lot more about fuses than I ever thought I   would and there's a whole bunch more to learn  we're just scratching the surface   here hopefully the thing you've learned coming out  of this video is that all fuses are not the same   even though they're the same color they might  look the same you pretty much pay for what you   get I'm not saying that all aftermarket fuses  that you buy off of Amazon or eBay are garbage   but a lot of them are Amazon and eBay sell good  quality fuses to the name-brand the bus Bussmann   fuses the Littelfuses and I'm sure there's other  brands that are good too but that the point is   you just don't know what you do know is that the  major brand ones that you can actually download a   datasheet for and with performance curves and  performance specifications are most likely to   be good quality fuses that should protect  the circuits in your vehicle the way they   should if you can't find a datasheet or even a  manufacturer on the name of the fuses only the   distributor then chances are those fuses are no  good and you should never use them throw them   away don't buy them tell your friends don't buy  them I'm going to hang on to these just for a good   example of a bad set of fuses but I would never  put these in a vehicle thank you for watching

Channel: WeberAuto

Views: 37,923

Keywords: Chevrolet, AutoZone, Hybrid, Resistance, Weber State Automotive, Cell Groups, Oh My!, UAT, Professor, Tesla Model 3, Prius Prime, Guy in wheelchair, NATEF, Aisin, ASE, CAT, Prius Plug-In, Bussman, Fluke 87, Littelfuse, fuse resistance, FCA, Nissan Leaf, Toyota, STEM, WSU, Advance Auto Parts, John D. Kelly, Ford, THS, Fuse Testing, milli-ohm meter, Walmart, Weber State University, Volt, NACAT, CCAR, Hioki RM3548, O'Reiley Auto Parts, How to test a fuse

Id: nELwmfAOz_I

Length: 34min 5sec (2045 seconds)

Published: Sat Jul 28 2018