How to Replace a Fusible Link (Car won’t Start)

How to Replace a Fusible Link (Car won’t Start)


Hey guys Chrisfix here watch what happens when I try to start my truck
You could hear it click, like the starter was about to engage
But now there’s no power at all not for the radio* dashboard* interior lights
It’s almost like someone disconnected the battery completely this problem is caused by a bad fusible link
so let’s go check out where the bad fusible link is located if
We look into the engine compartment right off the red battery cable
There are three fusible links if I wiggle these wires around listen to this
You can hear the battery basically reconnect and the truck prime’s itself because the keys in the ignition
Usually the engine will start after I mess around with it like this, so let’s start her up
And I want to show you another problem. I’m having
You can see the speedometer needle is jumping around
I’m going to go and wiggle the fusible links and let’s see if the Speedo stops bouncing around
[yeah], so you saw the needle just dropped when I messed with the wires, so that’s definitely our problem
Now that you’ve seen what a bad fusible link could do let me go show you how to replace them
So what is a fusible link real quickly a fusible link is pretty much just a wire with a really really thick
Rubber insulator now the idea is just like any other fuse when there’s too much current going through this wire the fuse breaks
So pretty much the inside metal burns up and the reason why this works is because you could see these are skinny wires
this is an 18 gauge
And this is a 12 gauge and look how thick these wires are down here that these
Fusible links are protecting these wires are pretty thick and the currents going to go through these thin wires
So if there’s too much current or you get a spike or something these will burn up
But since it has an extra thick rubber insulator on the outside you won’t start a fire, so it works
Just like any other automotive fuse. The only difference is this is a wire compared to those normal plastic fuses
You’re used to or the clear glass fuses. You’re used to remember [anytime] you work with the electrical system
disconnect the battery terminal first on the negative side, so
Let’s go cut this open and see what it looks like inside
So if we look where our three fusible links [attach] to our main wire right here
You can see there’s a lot of corrosion the corrosion was causing a bad contact and the fusible link itself actually didn’t blow
It’s just that the contact in here
Maybe it melted a little bit and it got bad so it needs to be replaced [so] let’s go see how to do that
Get in here. We’ll cut out all these fusible links. So these three fusible links
Attach this main wire right here
Okay, now that we got those disconnected. Let’s go just connect the other side
so this straight red one back here [only] had the two 12 gauge fusible links going to it and
Then this black and red one up here had three the two 12, and this one 18
I’m also going to replace the 18 just because we caught it and
You might as well replace them all since you’re in here
Okay, since the area where my fusible links are located [is] really tight. It’s hard to get good camera Angles
It’s also hard to work with all the cameras in there
So I’m going to show you right now the proper way to attach a fusible link to a normal wire
so here’s our normal wire – black wire and
Then here’s our fusible link that we’re going to be attaching so whenever you’re doing wiring
It’s always good to have something to hold your two wires these things are cheap is like five bucks
I’ll put a link in description to where you can get one it. Just makes your life a lot easier
So the first step is
You want to get your fusible link and you want to get the wire that you’re attaching the fusible link to and?
You want to blend them together?
so you’re pretty much just pushing it together and then twisting the wires around each other, [so]
[after] you get your wire, and the fusible link attached. They’re kind of meshed in together like that
You always want to add some type of crimp when you’re doing fusible link jobs. You just need a small crimp nothing big and
Close it up now
[normally] the wires wouldn’t be this stripped. So you would have this much space. It’d be a little bit tighter
Just because you don’t want this much space of exposed wire, but this is just for demonstration purposes
So [you] want to try to have less stripped wire now the wires that the fusible link attached to were thicker than this?
So you’re going to have to use a heavy-duty soldering iron because you want to transfer the heat from the bottom up
through you never melt the solder right onto the copper you want to hold the heat underneath and
Heat up, the whole metal here, and then add the solder to that now. I’m using lead Solder has a lower melting point
It’s just easier to use remember whenever you’re using something with letting it make sure you wash your hands after you’re done
So we put the heat from the soldering gun at the bottom here, and then we add the solder at the top
I’ll do the same thing to the other side
Okay, well, it doesn’t look too pretty it was done
Properly a good soldering job will look something like this
But in my case the solder was drawn through the strands and the connection is strong
So we’re good to go just doesn’t look that pretty
Next step is to use heat shrink tubing you want to get enough to cover the spot
You’re trying to heat shrink plus overlap each side of the wire and this will make it watertight
So just slide this over
Go all the way down and across
Slide it up. Just like so now grab your heat gun
Good, and you’re done
Okay, let’s go check it out. See what we got
So we’re able to join our fusible link to our main wire and I mean, I’m I’m really pulling on this hard
This is not coming loose. We use the crimp
We soldered the soldered melted through the strands of copper, and then we heat shrink it
And that’s the setup. We’re going to do this for all [three] of our old fusible links now
I’m not going to go into detail when I’m replacing the fusible links in my truck you saw how it’s done
just going to give you a quick overview of what I did, so let’s do it
so I had to clean the copper wires of any corrosion with the dremel since I couldn’t cut back these wires because it was so
Short already the rest after that was the same
Use a crimp melt the solder through the wire so that you have a good strong connection
Then use heat shrink to make it watertight one thing
I should mention is don’t forget to put the heat shrink on your wires before you crimp and solder everything together
Okay, so if we come in here we can see our fusible links are all set up they look really good
I’m going to wrap this in black tape in a few minutes. I just want to go start the car
Make sure it runs. So we’re going to go and put this negative ground
right on
Tighten that up, so it’s snug, and it’s not going anywhere, okay. let’s go start her up
beautiful
She’s running good the speedometer isn’t bouncing around. There’s no weird electrical gremlins, okay?
That’s a job. Well done. hopefully this video was helpful
If it was remember to give the video a thumbs up also if you’re not subscribed hit that subscribe button

100 Replies to “How to Replace a Fusible Link (Car won’t Start)”

  1. You're a freaking genius compared to Scotty Kilmer, swear to god he'd just tell you to replace the ignition switch! I watched his video on how to repair a no start/no power condition,(Fixing a Dead car With No Electrical Power) , no mention of fusible links.

  2. wish i would have seen this earlier. my car had the same problem and i couldn't figure it out took it to 3 different mechanics and the last one changed the whole ignition motor costed a lot. It works now but this seems like a more easy and cheap way.

  3. Pretty much this exact thing happened to me when I jumped my car with the polarity reversed. Everything seems normal when you put the key in, headlights work, fan and dash lights come on, but when I go to start it, everything just dies. And the dash lights and radio will flicker. Is this a fusible link? A fuse? Worse? 1998 3.0 Ford ranger

  4. is it wise to add a bigger 4 gauge power wire to existing one or replace stock one with 4 gauge? I upgraded my alternator from a 90 amp stock to 160 amp. I’m having some charging issues at high rpm’s. Should I also replace the fusible link to a 160 amp fuse?

  5. It wasn't really propper soldering. To get it propperly you will need flux and a bit different technics. And the worst that youe soldering is pretty dangerous and even may catch fire. So if you don't wan't to see ur truck burning one day, you better redo it. I'm not any kind of professional, i'm still learning, but in the institute of radio engineering or such. don't really know how to translate it right.

  6. I have a 1976 GM dump truck 1 ton that has two fusible links though they are working right now I am going to be doing some electrical work to add some circuits and I don’t like them because they are turning green I’m going to replace them with easy to replace maxi fuses at the rated amperage the circuit can handle then I will know when they are blown and are easy to fix.

  7. Chris, I have a 2002 ford focus se. it starts, runs for a minute then dies. I replaced the battery, fuel pump and fuel filter and still get the same results. the car sat out side for a year with a few gallons of gas in the tank. i'm getting a can of heet to hedge against water condensation. I've also swapped out the fuel relay.  next is checking the ignition switch.  What would you recommend?

  8. I leaned about fusable links the hard way in 1995 with my then girlfriends Jetta. I wish I had this video back then, good work Chris!

  9. Hey man, great video. Two questions. First one is where did you get those copper band clamps (3:46)? I looked on Ebay but found nothing. I may have been using the wrong keywords.

    Those would make holding the wires together before soldering much easier rather than the two methods you mentioned in another video (Western Union and something else). I've got one of those roach clip tools like you are using which is great on a work bench but it's hard to use it when soldering wires together in an engine compartment.

    Second question: Does solder have a shelf life? Reason I ask is back when there was Radio Shacks, I bought some very thin solder (maybe 25 years ago) and it worked well for years but here lately I can't get it stick very well. It tends to ball up. I think the flux or rosin core in it has broken down. I thought it maybe my soldering iron wasn't getting hot enough but I think it's the actual solder.

    Reason I found your particular video is The headlights on My Citroen 2CV are not protected from the factory and the car suffered an electrical fire at some point in the car's life and someone had repaired the harness.

    I went through a replaced all the corroded connectors. I considered added some in-line fuses to the headlights. I thought about mounting them directly behind the headlights but that is too far down stream to protect the wiring.

    I got some of that 1" ID insulation wrap to go over the wiring in the engine compartment and thought removing a section of each wire (four) going to the headlights and splicing in some fuse-able links. That way the insulation wrap will go over all the wiring easier than using in-line fuses.

    Best I can figure out the wiring going to the headlights are 14 AWG (actually metric). The current draw one each high beam is about 4.5 amps. So I chose some 18 AWG fuse able links. I read your supposed to drop down 2 AWG sizes. I figured fuse-able links would have an amperage rating. So if the headlights are pulling 4.5 amps does 18 AWG fuse able links sound OK?

  10. You've taught me sooo much. and I've turned around and fixed sooo many people's cars and then they ask how I learned and I say there's this awesome guy on youtube giving out lessons for free on this shit and they're like nah way! thats cool. thanks for fixing my shit. see ya!

  11. Just FYI, that same problem can be cause by corrosion on battery terminals or connectors, especially on large amp drawing systems, for instance a 7.3 PSD that requires 900 amps to turn over. Corrosion causes not enough current to be able to flow and you get that exact same result. Turns on, almost wants to start, then no power left.

    Clean battery terminals and connections and it will go away.

  12. also that problem might be caused by dirty battery terminals, just clean them and everything should be good.

  13. Chris, I have used regular fuses in a pinch. Is this something you would recommend or just as I get by?

  14. It's an old video, but I just watched it and learned about something I never knew existed. Now I'm going to go look for these on my cars. Nice work as always @ChrisFix.

  15. Chris can you tell me please where is the central fuse on 2008 Toyota Corolla? I have a big ploblem on my car. Thank's. S.O.S.

  16. Don't crimp and solder. Just crimp. Soldered joints have the tendency for cracking. A good crimp is more reliable than a soldered joint in an engine. Wonder why absolutely no connections in the engine bay are soldered on wiring?

  17. Chris good soldering job just a quick tip. Im a plumber and when we solder copper piping we have to make sure the copper pipe is cleaned (using abrasive cloth/sandpaper) If you want the solder to stick better try cleaning the wire with the cloth to get the debris off. Solder will only stick properly on clean metal.

  18. I have a 1976 Chevy c10 I replaced a alternator I put the hot wire on the ground so I need to replace my fuse linkage I have no power from the hot wire going to the alternator

  19. Hi ChrisFix, I have a Buick Regal 2011. The engine off automatically when I’m accelerating sometimes from slow speeds. I start the car again and it works fine for a few days. Sometimes, I would have to wait for a few mins for the car to start again as it won’t even crank. The battery seems to be fine when the engine shuts off as I can listen to radio or the lights on the dashboard stay on. I took it to a mechanic and he couldn’t figure out what the problem is. Can you help?

  20. Hey Chris i have almost the exact problem when starting the car, my alternator tested bad at my local shop and after replacing it these same symptoms came back with, could this issue also pop up as a bad alternator on a diagnostic?

  21. I have a 2010 mustang…the dash goes completely black and the system stops charging…the battery and alternater checked out fine…does anyone know what the problem could be?

  22. Chris fix I don’t know if you answer the comments. But I’m having a problem with a 77 280z. It’s been parked for 20 years. I put a battery in the car and there’s no power anywhere. Any ideas. Thanks

  23. Never put heat shrink over a bad soldering job. The sharp edges on the solder the heat shrink. Even worse if you wrap it in black tape. These things have happened to me. And to improve heat transfer you must melt some liquid solder onto the wires. From the top first and then move the iron to the bottom but keep the solder on top. That is why your job looked so crappy. I didn't win the high school soldering award and then spend a lifetime in electronics for nothing.

  24. As an electrical engineer (part time), that method of soldering is a bit rough! You just need to work on the soldering, it shouldn't look like a bubble of solder around the wire, the wires should look like they're turned silver and bonded like weld. The rest is amazing, keep up the good work! Oh and use flux to make it easier!

  25. I am having the same issue. The beginning on November of 2018 I replaced the gas tank fuel hanger and pump assembly and pump. It's doing the same thing. It refuses to start. The battery is a year old. I replaced the alternator starter oil pressure sending unit distributor. It does the same thing. It refuses to start unless you dump fuel into the throttle body. Just what could be wrong? I also replaced the fuel filter. What am I doing wrong?

  26. I've been repairing my own vehicles for around 4-5 years now, learninig from YouTube videos like yours, and I've probably had up to 3 vehicles with this problem. I'm glad you made this, gonna check my Ford Escort to see if this is its issue…hopefully it is.

  27. Uh the solder wont work without flux. And you always use lead solder on copper. Thats what i noticed about a lot of you tube tutorials,.they leave out at least one important detail that makes it work..

  28. Mr. Fix-It I'm not a fan of the bolt on battery cables more like the ones that crimp on and I or solder or crimp on I think they're better those tend to corrode can you show us fix a nose one time for the batteries thanks

  29. Hey Chris, I know this is an old video, but I have a ranger and in the past I had this same issue, but the issue kinda stopped (other than when I drive it’s like all power was completely lost, like a major stall almost like the truck completely dies). That still happens sometimes not as bad as it was when these issues where bad though, now it’s minor. The question is, now I sometimes have a no start situation, but no power is lost, just no click nothing (lights stay solid). Could it be related to the problems I was having a couple years ago, (thinking after this video, fusible links?) I swear I know my 01 ranger top to bottom inside out, but them fusible links lol when you pointed them out along with that issue, my mouth dropped

  30. Chris, I would first like to say thank you, this was incredibly helpful. I was wondering why you disconnect the negative ground instead of the positive ground?

  31. Hey chrisfix. I replace the battery and the alternator after a los charging to the battery but . That Didn’t fix the problem. What can I do to faint the problem why is not charging.

  32. Can I just use regular 12 gauge wire instead of some special fuseable 12 gauge wire? What’s the difference, or is there one?

  33. My lights started flickering on and off my gages started acting crazy and my Radio on and off by the firewall i found a wire Thats link into 2 wires burnt feels stretched i have 79 blazer going to fix that wire hopefull thats the problem

  34. I liked this video a lot because of your soldering job. I need to fix my compass/ thermometer on my truck and have been afraid to do so but after seeing this video, I can see that it doesn't have to be picture perfect for it to work. Thank you!

  35. Protip to anyone trying this: Melt a little solder on the tip of your iron before heating up the wire with it. Having a wet (tinned id the term) tip on the iron transfers the heat better!

  36. I have a Ford Expedition 🤦‍♂️ but my truck did the same but they said my fuse link or link fuse need to be replace. The cable that goes from the alternator to the positive terminal. But my truck was acting like it was possessed turn on my four wheel drive,dashboard going crazy and now it says check charging system,already replaced battery and alternator

  37. Hey good good tips could this be the reason my battery is draining and also battery only stays half way but when it reaches operating temp then all the sudden my batter shows a full charge any ideas new alternator water pump pulleys and fuses as well

  38. Really enjoy the video wish I could have come across it a week ago
    After my truck died and it ended me to fusible link coresite and it taking it to the shop because I didn't know what was wrong or even where to start looking

  39. Thanks! I had no idea what those cables did, today my mechanic said they needed replacement, it's an 83 Subaru Leone, so you could imagine how bad they can get, and I had the same issues you mentioned but couldn't find the cause.

  40. Oh man I was looking for this exact problem and didn't know how to describe it. Thanks a lot. Blessed youtube algorithm.

  41. Your soldering job looks crappy because you forgot to add flux always always use flux when soldering.
    I think it cleans the joint as well as allows better flow and prevent oxidation.
    I also use lots of solider and my joints come out looking all right even though my soldering skills suck.
    Also I think they make soldiering wire with flux inside still I allways flux more .

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