MattPlaneCrank Launches 100 Amp Fuse Is **** Club

[Penelope Stopit]

MattPlaneCrank said:

I’m now a fully paid up member of The 100A fuse is club!

The club welcomes its second soon to be member

RUSSELLM said:

I’m with Penelope... Next time I get chance, I’ll stick a new lead in from battery to alternator, and do away with that fuse.

I seem to recall last time I was under the dashboard, there was a mega fuse sited there above the engine ecu. It seems to get seldom mentioned on here, so I presume it rarely fails. If you haven’t already spotted it, and my memory is ok.... There’s a positive lead from battery to LHS of dash, then a Mega fuse, then the positive lead out to the fuse box.

The club welcomes its third member

Do hope I,ve got this right, Mr Cerbera certainly looks like more than half a member

Mr Cerbera said:

I cannot, for the life of me, imagine a Friday Afternoon Meeting of post-lunch, drunk Engineers deciding that bolting a feeble (yet very important) article right in the Crotch of a high-revving, innately off-balance motor, buried under fuel injection and Sparkplug cables, fuel pipes and an induction system was a good idea.

Edited by Penelope Stopit on Saturday 10th April 15:36

[Classic Chim]

What I’m seeing is a 20 year old fuse holder and rusting nut.
Being a man of little electrical genius I’m assuming that’s resistance created by the equally old knackered cable that’s popped the fuse.
Did it’s job

[spitfire4v8]

Mattplanecrank should leave the group that says the 100A fuse is **** and join the club that asks why is my service agent not doing their job properly ... !!??

[Mr Cerbera]

Brilliant Thread, Pen
________________________________________________________________________________________________

Matt probs had the same level of 'registered dealer' service that I had, who let this through 2 x 12K services....

Edited by Mr Cerbera on Friday 9th April 09:55

[Digga]

In my many years of owning a Griffith, only two things ever stranded the car at the roadside, and this including trips to Italy and back, hammering along the autobahns:

1. Main crank pulley, incorrectly torqued/threadlocked by servicing dealer.
2. 100a fuse, on way to Le Mans in 2003.

Can't claim to know much about auto electrics, other than "don't let the smoke out of the wiring harness".

[ukkid35]

I could post a pic of a faulty 100A Midi fuse, but there's no point because it will look just like a new one

They seem to break down over time, causing rev counter flickering, and other random issues

It's always worth carrying a spare (and the means to change it)

[Digga]

ukkid35 said:

It's always worth carrying a spare (and the means to change it)

And, of course, knowing where it is located in the first place.

You can change very easily if you know how/where, even at the side of the road.

[MattPlaneCrank]

Penelope Stopit said:

MattPlaneCrank said:

I’m now a fully paid up member of The 100A fuse is club!

Thanks for making my predicament official Pen!

In order to leave the club I seem to have inadvertently created I have ordered the appropriate properly designed waterproof fuse holder and other parts suggested by Gordon. I’ve also obtained the weapon below to overcome the 100A fuse of doom. I may also use it on my so called TVR specialist garage. Wish me luck folks.

Matt

[Penelope Stopit]

Mr Cerbera said:

Brilliant Thread, Pen

Thank you Mr Cerbera

[Penelope Stopit]

Mr Cerbera said:

Matt probs had the same level of 'registered dealer' service that I had, who let this through 2 x 12K services....

Frightening

[Penelope Stopit]

MattPlaneCrank said:

Thanks for making my predicament official Pen!

Please MattPlaneCrank, simply placing your post on the pedestal it deserves to be on, credit where credit is due and all that

[Penelope Stopit]

MattPlaneCrank said:

I’ve also obtained the weapon below to overcome the 100A fuse of doom. I may also use it on my so called TVR specialist garage. Wish me luck folks.

Matt

Nice crimpers, what size do they go up to?

[Penelope Stopit]

notaping said:

I got fed up with failures of this fuse. None of which were electrical, but all mechanical due to vibration or water ingress. I ended up mounting a more robust holder on the wiper mech box - which gives real easy access.

At least a person can swing on their nuts when using this type of fuse holder

[Penelope Stopit]

Classic Chim said:

What I’m seeing is a 20 year old fuse holder and rusting nut.
Being a man of little electrical genius I’m assuming that’s resistance created by the equally old knackered cable that’s popped the fuse.
Did it’s job

Ok I'll bite

The nut isn't rusty, it's been getting hot

[Classic Chim]

Penelope Stopit said:

Ok I'll bite

The nut isn't rusty, it's been getting hot

Whats the brown stuff, copper slip!
Heat, I gathered that much.
Like so many things I think the 100A fuse gets a bad rap.
Do a poll. How many have actually blown over the years compared to how many ever get checked/ changed.

What is actually wrong with the fuse holder in the photo above?
There is clearly a problem with the cable.
I’m genuinely curious. Tvr owners love nothing more than blaming the car when a 20 year old fuse blows, beats me

[MattPlaneCrank]

Classic Chim said:

Whats the brown stuff, copper slip!
Heat, I gathered that much.
Like so many things I think the 100A fuse gets a bad rap.
Do a poll. How many have actually blown over the years compared to how many ever get checked/ changed.

What is actually wrong with the fuse holder in the photo above?
There is clearly a problem with the cable.
I’m genuinely curious. Tvr owners love nothing more than blaming the car when a 20 year old fuse blows, beats me

OK maybe I'm guilty of overdramatising the situation.....following PJ's original post I investigated my 100A fuse, noted that it was corroded, had been getting hot (P=I^2R) and the nylon insert in the nut had melted. It hadn't actually failed but clearly that event wasn't to be far in the future! When I loosened the nut to remove the fuse it cracked.

The cable appears to be fatigued or corroded, maybe the heat from the fuse has accelerated the failure?

I'm just glad, with everyone's advice, I've avoided a breakdown. Despite being built in a shed in Blackpool 20 years ago and not maintained to the best standard my Cerb hasn't let me down in the 2 years I've owned it.

The crimpers which I've borrowed go up to 35sqmm, nice bit of kit and I expect they were rather expensive.

Matt

[Classic Chim]

I think the cables are prone to it due to the tight bend.
My main + cable at the battery end looked like yours and it was bent in a very similar way probably from day one.

The only issue with the fuse is it’s location is my thought.
I thread a small cable tie around it to keep the door shut as a personal comfort blanket

[Penelope Stopit]

Classic Chim said:

The only issue with the fuse is it’s location is my thought.

The only issue with the Cerbera 100 Amp fuse is it's existence

There is a vast difference between comments with and without reasoning

As ever, I rest my case

Often wonder how many cars have suffered a blown 100 Amp fuse

There are many posts to this forum regarding failed/broken fuses, have not come across topics about blown fuses

There's a reason for the lack of topics about blown 100 Amp fuses, it being that the fuse is protecting a short length of cable

As long as good sleeving and fasteners are used to protect the run of the alternator main positive supply there won't be a problem (Yes I know what happened to the Titanic)

Alternators don't easily short to earth, if a diode goes short circuit it will not remain short circuit as it will burn out before overloading the heavy duty supply cable

Alternators can short to earth at the main positive terminal if its insulation is damaged due to incorrectly tightening the cables eyelet terminal onto it, even then it's not easily done with a Cerbera alternator that has a massive insulator plate

Manufacturers fuse certain circuits to cover themselves from liability due to them having no say in what goes on with their vehicles once they have left the factory

Not meaning to offend with what some class as bad language.........................................................The 100 Amp fuse is a load of bks

[Classic Chim]

Penelope Stopit said:

The only issue with the Cerbera 100 Amp fuse is it's existence

There is a vast difference between comments with and without reasoning

As ever, I rest my case

Often wonder how many cars have suffered a blown 100 Amp fuse

There are many posts to this forum regarding failed/broken fuses, have not come across topics about blown fuses

There's a reason for the lack of topics about blown 100 Amp fuses, it being that the fuse is protecting a short length of cable

As long as good sleeving and fasteners are used to protect the run of the alternator main positive supply there won't be a problem (Yes I know what happened to the Titanic)

Alternators don't easily short to earth, if a diode goes short circuit it will not remain short circuit as it will burn out before overloading the heavy duty supply cable

Alternators can short to earth at the main positive terminal if its insulation is damaged due to incorrectly tightening the cables eyelet terminal onto it, even then it's not easily done with a Cerbera alternator that has a massive insulator plate

Manufacturers fuse certain circuits to cover themselves from liability due to them having no say in what goes on with their vehicles once they have left the factory

Not meaning to offend with what some class as bad language.........................................................The 100 Amp fuse is a load of bks

Does this apply to the Chimaera in the same way?
It does seem odd it’s there at all but I can live with it as I know nothing about this subject in truth.

[RUSSELLM]

I’m with Penelope... Next time I get chance, I’ll stick a new lead in from battery to alternator, and do away with that fuse.

I seem to recall last time I was under the dashboard, there was a mega fuse sited there above the engine ecu. It seems to get seldom mentioned on here, so I presume it rarely fails. If you haven’t already spotted it, and my memory is ok.... There’s a positive lead from battery to LHS of dash, then a Mega fuse, then the positive lead out to the fuse box.