Fuse Link, must have in glove compartment

[Cyprs]

Brought home my 92 diesel, cig lighter shorted out, truck would not start due to ignition out, 80% of accessories out in fuse box. I traced wiring to fuse links, for heck of it, I did a twist tie joint with fuse link splice and everything worked, (I did fix the cig lighter short first). Anyway, I later sodered the link and all is good. I now have 3 feet fuse link, electricians tape and side cutters in truck, I now know where the fuse links are, (front driver side fender half way between battery and fire wall), not bad idea for anyone to know where these fuse links are in their vehicle and be prepared, saves a tow fee, garage fees and long wait on highway stranded. Napa sell the stuff. (I then used fuse link on my cig lighter repair and will use it on any other accessory when I rewire to save blowing out other accessories, handy stuff. Just thought I would pass on my experience, I had thought I had hundreds dollars wiring damage prior to digging into manual and discovering fuse link.

Cyprs

 

[motorguy222]

Something that you may need to check,fuse links are usually rated at differing amps,just like regular fuses are.If you replace a fuse link with a higher amp than what has actaully blown,you are in danger of either a fire or frying more than just the link.A fuse link is for the most part,a glorified fuse.

 

[brianl703]

Actually the trend is to use fuses instead of fuse links in newer cars. This is considered an improvement in safety and servicability.

Fuse links are thus "deglorified fuses".

 

[labman]

Are the fusible links much more than a short section of smaller wire designed to localize failure near the battery or alternator?

 

[motorguy222]

Fusible links were used quite extensively at one time,so they were at one time,a 'glorified fuse'.
They are in essence what labman has stated,a short wire between sections of 'normal' wire that is for all intents and purposes,a fuse.The link is covered in a thick hard plastic that many times will not show any sign of blowing or failure.
I know this from experience.

Fusible links were and may still be used in several areas in the wiring of a car.
GM used to have,and may still have,3-4 located at the starter connection.
They are/were also used at other areas in the wiring of the vehicle.
I had much rather have a wiring system that uses a fuse for protection.

 

[labman]

Fusible links protect the wiring between the sources of power and the fuse box. They have a function where most of your power comes off the starter terminal.

 

[motorguy222]

quote:

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Originally posted by labman:
Fusible links protect the wiring between the sources of power and the fuse box. They have a function where most of your power comes off the starter terminal.

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You have for all intents and purposes,hit the nail on the head.

 

[brianl703]

quote:

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Originally posted by motorguy222:
Fusible links were used quite extensively at one time,so they were at one time,a 'glorified fuse'.
They are in essence what labman has stated,a short wire between sections of 'normal' wire that is for all intents and purposes,a fuse.The link is covered in a thick hard plastic that many times will not show any sign of blowing or failure.

---

Until the early 90s, there were no high-amperage fuses (over 40 amps) available for automotive use. Then the Megafuse and other similar high-amperage fuses, such as the MAXI fuse, also became available. Until those high-amperage fuses became available, the only option for protecting high-amperage circuits was a fuse link.

Ford fuse links are covered with an insulation that bubbles and discolors when the link melts.

My 1996 Ford Contour has NO fuse links anywhere in it.

Maybe some other vehicles from manufacturers who don't pay as much attention to product improvement still use fuse links

 

[motorguy222]

I have seen several fuse links that were low amp rated.It seems that auto makers were using the links in place of fuses regardless of the amperage.Why? more than likely they were cheaper to use than wiring in fuses and their respective fuse panels were.
The high amperage reason may be true,I dont know.
I do know that there are low amp links,I have a manual that shows their ratings in an auto.
I think they were used as a way of saving money.
Think about it,if a 40 amp fuse link can be made,there is no reason that a 40 amp fuse could not be made.
It all seems to come down to cost.

"Maybe some other vehicles from manufacturers who don't pay as much attention to product improvement still use fuse links."

As I stated in my other post,they may or may not be used now.I dont know as I dont own a new car.
I also dont do electrical work unless it is an absolute have to case.
Also,my post should say that the links can SONETIMES,not many times go bad without any sign of such.My bad,I really need to stop posting after midnight or at least preview them better.
Oh well,I am not perfect.

[ September 09, 2004, 11:53 AM: Message edited by: motorguy222 ]

 

[brianl703]

I've never seen fuse links rated in amperage--they seem only to be rated in terms of wire gauge, and then the general rule is to use a link 4 sizes smaller than the wire it's protecting.

So a 10 gauge wire should be protected by a 14 gauge fuse link.

(I've tried to find information listing the amperage rating of various gauge fuse links, but I haven't had any luck).

If there were fuse links rated in amperage that needed to be replaced, I'd replace them with a Maxi-fuse and a Maxi-fuse holder.

 

[labman]

I would be interested in what Cyprs had so much trouble with the fuse links. I don't ever remember a problem with one. I kept a couple of Pontiacs until they were 10 years old with them and never a problem. On the other hand, fuses sometimes seem to blow just because they are old or something. I don't, but some people routinely replace them every few years.

As for the rating, if the link is 14 gauge, look up the current rating for a 14 gauge wire. On a wire that only feeds one load, size the fuse to the load.

 

[motorguy222]

I did not explain a fuse link as well as I should have.They are for all intents and purposes,a fuse.They are 4 sizes smaller than the wire they protect.

However,a fuse is rated as amps,not volts.Look on any 12 volt auto fuse and it will say,12 volts.It will also say how many amps that it is rated for,hence the 10,15,20,25 on a fuse.The amperage is usually the culprit in the blowing of a fuse.

A fusible link works in the same way as a fuse.They are rated at 12 volts just as a fuse is,however,if too many amps are pulled,it may and can,blow.They protect a circuit in the same way.While a fusible link may not be rated in the technical sense as amperage,amperage is for the most part the killer of such.

The amperage is the strength of an electrical current,when a fusible link or fuse blows,something is pulling to many amps for the respective circuit.When too many amps are pulled,you get a blown fuse/link.When the amps flow too fast,you get heat,heat melts the link.

 

[brianl703]

How many amps does it take to blow a fusible link in the 14 or 16 or 18 or 20 gauge sizes?

What would be the equivalent amperage Maxi-fuse that could be used to replace that specific gauge fusible link?

I've looked for this information..I can't find it. I know it's out there somewhere, obviously the engineer who specified the fusible link must have been working with more specific data than "use a link 4 sizes smaller than the wire it is supposed to protect".

 

[motorguy222]

"How many amps does it take to blow a fusible link in the 14 or 16 or 18 or 20 gauge sizes?

What would be the equivalent amperage Maxi-fuse that could be used to replace that specific gauge fusible link?"

That is a good question.I suppose the reason that such seems to be so hard to find is to keep a person from wiring in a fuse in place of the link.
When the cars are newer,you would have to get the links from a dealer,money,money.
As you said,there is probably a chart or something somewhere that will state the amps needed to replace such with a fuse,finding it is the problem.

 

[Cyprs]

Labman, I just recently bought the truck and found out something must have happened at some point to my wiring, it seems to have been redone and all wrapped with electricians tape. I question the grounding of this wiring job, what I believed happened was 4 other wires seemed to have grounded to a terminal which this cig lighter also grounded to. When the short happened it blew out other accessories and 75% of my accessories, there was no power to 75% fuse box, my manual seems to show fuse links to the fuse box in schematic, I think I have the previous owner to thank for eliminating them in his rewiring.

I did replace the 20 guage fuse link wire with a 20 gauge fuse link repair. This is first time I have ever run into fuse links, all other vehicles have had fuses, in this Dodge there is no under hood fuse box, just links. I am told the links protect the computer from blowing out, these llnks are placed a couple feet from fire wall between the battery, the computer is against inside fender beside battery on this 92 dodge. These links will blow prior to reaching computer, Dodge seems to have goal in mind in protecting computer and let the fuse box take the rest of wiring problems under dash. It is the custom wiring job done that seems to have cause my problems, my wiring is far from factory, I hope to fix things as they happen if they do, I cant rewire myself but I keep some fuse link handy for emergency.

I do pick a bone with Dodge though, there are about 6 fuse links that mould into a rubber housing which splice into two large wires from battery. I had to cut into that rubber housing to get to undamaged fuselink to make a proper soder splice. Why couldn't Dodge put 5 standard wires a couple inches out from that housing and then attach the fuse links to the standard wires, they could put these standard wires on each side of fuselink. This would allow the fuse link to burn out with no damage to standard wires to repair properly. Guess dodge wants me to go in and buy the 6 fuse link rubber housing for about $50.00 to repair (1) 5 inch fuse link wire. Dodge could have made a good system here, instead the fuse link burns out right into the rubber housing which houses 5 other perfectly fine fuselinks protecting other circuits, makes no sense to me.

thanks,
Cyprs

 

[JohnBrowning]

When I was actively working as a tech. the common field fix for fuseable links was not complicated at all. We were taught to replace the fuseable link with a short piece of wire one quage smaller then the wire it was protecting. It should be soldiered and shrink tubed. I was taught this in the USA.

 

[labman]

I am no fan of Chrysler, but they should not be held accountable for the misdeeds of the former owner. Even the best designs and workmanship can be messed up by an idiot. I think this thread has enlightened us all. I don't think my 77 Chevy LUV has any fusible links, maybe a later innovation. I haven't poked around my 02 Cavalier enough to have seen any yet. It does have fuses and more fuses, all new types meaning I had to go out and buy more to stock the glove box. When packing tools for my road trip last month, I threw in a wire cutter/stripper. Perhaps in the permanent stock, I will add some solderless connectors.

 

[brianl703]

In the case of Ford, they used fuselinks in vehicles that didn't have an underhood fusebox, to protect underhood circuits. They did use fuselinks for low-amperage circuits also.

Then they started adding a "power distribution box" under the hood and put everything that would have been protected with a fuselink on a fuse in there.

It's definitely cheaper to use fuselinks, but it makes troubleshooting so much harder. Plus fuselinks aren't quite as safe as fuses...they sometimes spew molten copper when they burn up.

 

[motorguy222]

Getting back to the use of a fuse link.As I stated in my first post,NEVER use a higher rated fuse link than the one that you are replacing.
This can be dangerous.
To replace a 25 amp link with a higher 30 amp link would be the same as replacing a 25 amp fuse with a 30 amp fuse.
What ever is being protected by that link/fuse is now in danger of overheating,burning out a curcuit and or,a fire.

 

[Cyprs]

I agree Labman, I dont hold Dodge responsible for the "idiot" who rewired my truck, the fuselink setup though was not tampered with, it was factory. My bone to pick with Dodge was this rubber fuselink housing without standard wires protruding from it with fuselink then attached directly to these standard wires. This would prevent the fuse link from melting inside the rubber housing making a repair easy without having to cut into this rubber housing or replacing the entire fuselink housing which means replacing 5 other perfectly good fuselinks. I do hold the rewiring culprit responsible for the short and other problems due to wiring. I did manage to soder the other side of fuselink easily where the fuselink had not melted and where there was no rubber housing. If I buy another multi fuselink housing I will soder in standard wire and add the fuse link on firewall side of these standard wires, this way I will have a fixable system, the way it should have been in first place, all circuits to computer will still be protected as they are now, there always seems to be a better way, guess armchair engineering is easier as in armchair coaching sports.
thanks,
Cyprs