25 replies to this topic

[gooley]

Just last week I finished fitting the battery to the boot in my Torana LC, 186 Red Motor and Fitted positive wire underneath car leading it to the boot and fitted earth from battery to chassis, also another earth from engine to chassis. With battery box, sealed battery with it venting outside.

 

My question is I haven't fitted a fusible link, Do I have to?

 

I don't see why you have to as the setup is basically the same anyway just has a longer positive wire.

 

I have read many posts on here and elsewhere and but seen many people say yes and vice versa.

I drove my Torana around today and had a good 20 minute drive and had no problems, it's running great.

Edited by gooley, 20 November 2013 - 06:58 PM.

[Rockoz]

The fusible link is fitted to the wire supplying the fuse box from the starter motor.

It protects the wiring from that point on in the electrics.

If there is a problem in the wiring it will blow hopefully before setting the wiring on fire.

Is it essential?

Having blown one on my LC years ago from the harness dropping on to the block and shorting I would say yes.

A fusible link in the main battery cable shouldnt be needed provided it has been installed properly. ie well secured and insulated.

[gooley]

Ok so to be safe I would want to fit one...

 

How do you go about buying one?

What Amp range should I be looking for?

[Rockoz]

If you have the original harness its already there.

If you have a new harness fitted its dependent on the wire size its protecting.

Pretty sure supercheap will have one of some description and any good car audio supplier as well

[gooley]

oh ok... I'm pretty sure it's original harness but I'll check for one anyway. I have checked on different types of fusible links and I'm guessing its the 'Wire Fusible Link'.

I'll check on it tomorrow

[Rockoz]

The original one will be the ring terminal that bolts on with the battery cable. About 4 inches along will be the join into the main wire. Plastic blob on the one I had.

[gooley]

Yep found the Fusible Link....cheers

 

I've been reading on Fusible Links with wiring about project cars and just wondering what are everybody's thoughts on replacing the Original Wire Fusible Link with a New type Fusible Link?

[Rockoz]

My thoughts are that it depends on how much of the existing wiring and fuse arrangements you want to change.

If you are keeping the existing fuse box use the existing fusible link.

Its suited for the application.

If however you want to put in a new fuse box and have it under the bonnet then look at a newer style.

The existing fuse box would at least need a good servicing at this age anyway and probably doesnt have the requirements for the stuff most people put in the cars these days anyway.

[Dr Terry]

the size of the fusible link is more dependent on the size of the alternator, original alt had an output of 40 amps, you could get away with fitting a 55 amp alt but much bigger and you could the blow link, when I used to fit the 130 amp bosch alts I always fitted an aux feed to the alt output

The charging current from the alternator to the battery doesn't go thru the fusible link, so alternator output has no bearing on the link's amp rating. The alternator's +ve wire goes directly to the battery +ve.

 

The fusible link only carries the current going to the car's fusebox, lighting & ignition circuits or anything else running off wire from the starter terminal lug.

 

Dr Terry

[hanra]

^ 100% agree.

[gooley]

Yeah I'm just saying... I find out what Amp rating the original fusible link is and then replace it with an updated fusible link.

 

Like this one... Replace the wire version to this

 

I mean i have researched and the wire fusible link opens circuits but may cause a flame.... whereas the new connector when it open cicuits there is no flame

Edited by gooley, 26 November 2013 - 09:19 AM.

[Rockoz]

Thats really just an enclosed fuse. 

What rating fusible link is standard?

What rating of the pictured fuse are you going to install?

Do yourself a favour and study closely the size of the fuse element inside a glass fuse. The thinnest bit if it.

Now have a look at the size of the wire it is protecting. There is a huge difference in sizes.

Then have a look at the size if the standard fusible link in relation to the wire it is protecting. There is not a lot of difference.

Now if you decide to replace it with the type you have shown, where are you going to mount it?

[RallyRed]

hi...just came into this thread a bit late......but always remember that if Holden made a couple of million cars  and not too many burn to the ground with electrical faults..then, although not perfect., they got it pretty right.......sometimes there is no need to re-invent the wheel unless there is a special requirement.

 

Regarding the cable from the boot/battery to the engine bay...if ts protected by sufficient insulation, grommets thru holes, split conduit etc etc...then it  probably doesnt need any more protection.

 

IMHO

[gooley]

Thank you for your opinion. I think I'll leave it as is.

[RallyRed]

Hi again Jason,

 

Hopefully I didnt come across as a smart arse.....just that I have the same in my LJ ( battery in the boot, big arse cable to the front, and the rest all factory standard)....so I recently pondered exactly what you are thinking about.

 

Decided in the end to leave well enough alone.

 

Regards

[S pack]

Hanra and Dr Terry ,check the wiring diagram for LC,LJ with the optional combined instrument cluster,the alternator output is are linked to the headlight,ign switches and the fuse box,then to the positive side of the ammeter,then the negative side of the ammeter through the fusible link to the battery terminal on the starter,I went and checked my LJ wiring and it is this way
Phillip

Correct.

[gooley]

Hi again Jason,

Hopefully I didnt come across as a smart arse.....just that I have the same in my LJ ( battery in the boot, big arse cable to the front, and the rest all factory standard)....so I recently pondered exactly what you are thinking about.

Decided in the end to leave well enough alone.

Regards

Lol. It's all good mate. I thought about it and understood your post. I didn't think you were rude at all, My reply comment wasn't supposed to sound rude as well because when I read it out loud, it does to me.

[Rockoz]

Fitting a fusible link to an alternator is a waste of time.

As an example. A 50amp alternator supplies 50amps. Plus or minus a little for tolerance.

Fit an 80amp fuse to a 50amp alternator, it will never blow because of the alternator. Because the alternator can only supply 50amps.

Once the alternator has reached its capacity, the battery supplies the required power. Under short circuit the battery may supply 1000s of amps. Thats why the fusible link is where it is.

Auxilliary feed off the alternator. Why? If the alternator is already at its capacity, the extra power will have to travel further from the battery to the alternator and to the auxilliary.

Provided the wiring from the alternator is sufficient to handle its output, no protection is required. 

The alternator can be considered self protecting.

Protection devices are fitted to protect cables. Nothing else.

 

[arrimar]

Auto elec told me that since no one was buying fusible link a lot of cable manufactures don't bother making it anymore. Since the majority of cars on the road have the replacement fuses like above he hasn't stocked any for years.

[hanra]

Hanra and Dr Terry ,check the wiring diagram for LC,LJ with the optional combined instrument cluster,the alternator output is are linked to the headlight,ign switches and the fuse box,then to the positive side of the ammeter,then the negative side of the ammeter through the fusible link to the battery terminal on the starter,I went and checked my LJ wiring and it is this way
Phillip

 

 

Yeah your bloody right mate, for LC/LJ.

 

 

 

LH/LX is a different kettle of fish

Edited by hanra, 27 November 2013 - 11:34 AM.

[Dr Terry]

Yes, that is correct, I was wrong, if the car has the optional (GTR) cluster. This only applies to cars with an ammeter, LH onwards do not.

 

But even then, the entire alternator output does not go thru the fusible link. Only the current going into & out of the battery goes thru the fusible link. The rest of the alternator's output goes to feed the ignition system, lights or whatever else is switched on that the time.

 

Dr Terry

[hanra]

Terry is correct again. Standard LC and LC with optional cluster use two totally different wiring layouts for this. Standard LC is the same as LH.