Jump to content
Naked Buell

Fusible links Questions

Recommended Posts

Hey guys. I have the 88 Rx and someone other than myself had replaced one of my fusible links with just a piece of wire and guess what?

Yep, a plug that wasn't being used touched the tranny while driving and smoked the link and left the lady stranded.

 

So I brought it home and repaired everything but I wanted to changed the fusible links with blade fuses and was wanting confirmation on the amp rating of the links.

 

So any of you guys with the ea82, could you look at your fusible links and tell me the colors from closest to driver to the front of the car?

The one that smoked I am trying to find out what size so I can replace. 

 

Mine go, fried one, green, red, green.

 

Can I get a confirmation from any of you guys on the ratings of the fuses?

 

Thx for your time too.

Share this post


Link to post
Share on other sites

Yeah man.. my 93 ea 82 fuseable links are from the dash to front

 

 

/black 1.25/green 0.5/red 0.85/green 0.5

Edited by Len Dawg

Share this post


Link to post
Share on other sites

I am not sure but are those numbers amperage?

If I change them to blade fuses do they make a blade fuse that low?

Share this post


Link to post
Share on other sites

Fusible links are just a section of wire that is smaller than the circuit wire and will melt before the rest of the circuit. There's nothing special about them. The number is the cross sectional area in square millimeters. You can work out what AWG would be close in cross sectional area and just use a section of standard stranded wire with spade terminals crimped on. I believe that black one is in the neighborhood of 80 amps. You could use a circuit breaker or one of the plastic enclosed fusible links from the newer stuff. It's not really a fuse because it's "blow curve" is different. Typically slower. 

 

GD

Edited by GeneralDisorder

Share this post


Link to post
Share on other sites

The fusible links are in the tens of amps range. Not unusual at all. They are in the main power distribution circuitry. I can try to find ratings a bit later. They are used because they are slow to blow, and way less spendy than regular fuses for the high currents would be.

Share this post


Link to post
Share on other sites

Fusible link specifications from my FSM:

 

Square area in mm - melt in 15 seconds current

 

0.5 -  80Amps

0.85 - 130Amps

1.25 - 190Amps

 

One of these is for the main alternator output, others are the fuses for the main power feeds to the fuse box.  Proper fuse size and location is important to protect against starting fires in the wiring.

Share this post


Link to post
Share on other sites

Don't take chances. Replace in kind. The black one is the most important fuse that runs the engine.

There is no "chances" being taken. When you fully understand how the system works you just replace with similar function. Fusible links are used on many vehicles and their operation is well documented. 80 Amp fusible link should be sufficient - the alternator output is 55.

 

The fuses, links, etc are there to protect the wiring and should be sized accordingly so the vehicle wiring will not be in danger of overheating.

 

GD

Share this post


Link to post
Share on other sites

Fried mine couple years ago putting battery in backwards. Was told the replacement was last in universe (or some such hyperbole). Was told at time that a Toyo truck had comparable part.

Share this post


Link to post
Share on other sites

Though it has been answered already...I went through the effort to look, so I can respond with the following:

 

black, green, red, green

 

I went to the recycling yard and grabbed all 4 of them as spares.

Share this post


Link to post
Share on other sites

So I swapped it out to a maxi- fuse big blade. But I can't see it having an 80 amp fuse on 10 gauge wire. I am thinking it would be better to have a lower fuse to pop before the current gets so high. Look at the feeder wire from the battery. It isn't that big, a 10 gauge as well. 

Maybe I am not seeing things correctly. Even if my alternator is 55 amps, how can I have a fuse that is 80 amp???

Share this post


Link to post
Share on other sites

I would have to agree, that's too much for a #10 wire. Do you have an ammeter? You could do a real-world check on the maximum your system could possibly draw, by turning on ALL your accessories, something you would probably never do anyway, and size your fuse just above that. Don't forget the rear defroster.  <_<

Share this post


Link to post
Share on other sites

Hey good idea. I am an electrician by trade and it just seems too much. I will do your idea and post what I find. Thanks Subaru Scott. 

Share this post


Link to post
Share on other sites

The maximum safe current in a wire us determined by the insulation temperature and such. Common building code ratings are for low temperature insulation.

 

The alternator can only supply 55 amps for a long time. It could do more for a time determined by when something fails due to overheating, so short overloads are ok. Also the battery is capable if pushing hundreds of amps, and that is the real danger.

Share this post


Link to post
Share on other sites

. But I can't see it having an 80 amp fuse on 10 gauge wire. I am thinking it would be better to have a lower fuse to pop before the current gets so high. Look at the feeder wire from the battery. It isn't that big, a 10 gauge as well. 

Maybe I am not seeing things correctly. Even if my alternator is 55 amps, how can I have a fuse that is 80 amp???

 

Because these aren't your fuses. Individual circuits around the car have fuse protection through the interior fuse box.  

 

If all is correct, the fusible links will never ever need to melt.  They are merely there to prevent a direct short to the battery in an accident or odd case of mice chewing or some other "dead short" to ground of the wires running between the Fusible link box and the main fuse box.  Where your actual circuit protection happens.

 

You don't want the combined loads of the accesories in the car to get anywhere close the Fusible link max.  But in the case of a dead short somewhere between the Fusible link box and the fusebox, it will try to draw as many amps as are available from the battery.....i.e. several hundred.  So as long as you have some sort of FL in there it will do it's job.

 

You can buy fusible link wire in rolls, of different gauges, and crimp spade connectors on.  Very easy.

Share this post


Link to post
Share on other sites

Like mentioned before, I did install a stereo maxi-blade fuse and put in an 80 amp. It also came with a 40 amp as well. So I understand what you are saying. The fuse should never reach that. I also checked all my fuses inside before connecting the battery and it did blow the ignition 15 amp fuse, which explains why the wife said the car just shut off. 

So I guess I will just keep the 80 amp in. I did eliminate the plug that wasn't being used that caused the whole headache so I should be good. I will post some pics later. 

Thanks guys. 

Share this post


Link to post
Share on other sites

Not sure if this feed is still active but is there any test I can do to test a fusible link and if so how do I do them 

I have a no start no spark 

Share this post


Link to post
Share on other sites
19 hours ago, Cormfra said:

Not sure if this feed is still active but is there any test I can do to test a fusible link and if so how do I do them 

I have a no start no spark 

Check for power on either side of them. Just like any other fuse. If in doubt, replace them temporarily with a section of wire with spade terminals. Do this  only for testing, use appropriately sized wire (approximately 2 AWG sizes smaller than the circuit),  and have a fire extinguisher handy in case something starts smoking.

GD

Share this post


Link to post
Share on other sites

GD is in the room ! It is a while, I had a question for you but has escaped me for the moment.

Those old FL can be in as new looking condition or a corroding mess just festering to leave you in the lurch.

Can just depend on what past 30-40 years has been like to them :)

In EA81 and EA82 they can be updated from the siliconey looking insulation fabric type to the Female Fusible Link

FFL for an acronym, like human females, leg length varies so the ones that fit have about 12 mm legs

And with a little help from my friends we arrived at the Do not swap colour of fabric for colour of FFL,  if you do you might double the rate at where new FFL will blow burning out your pride and joy first :(

What have we got in the EA82 ? Three colours? Red, green and black?

The simple way we worked out was to find the Subaru manual rating on each colour of the fabric ones first for reference

Say dealing with green fabric, shift across to green FFL to find its Amp rating cast in the clear plastic lid ( ignoring the 230V) 

if the green is 40A , you want to find an FFL with half that 40A , so 20A , will be a different colour, but will have 20A in the clear plastic lid.

Using this method for years now, like the boys following the advice from auto elecs, and internet saying go colour for colour ( possibly doubling the load needed to blow them :( )

We have had no problems. If we had underrated the FFL you would think we stuffed up, only on the side of caution.

Next time you at a wrecking yard, see if the fabric ones have been snaffled or corroded

 

1590275134321-582625133.jpg

Edited by Step-a-toe

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×