Total electrical failure – could this happen to you.....?

Total electrical failure – could this happen to you.....?

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Discussion

noisynorton

Original Poster:

18 posts

143 months

Wednesday 28th May 2014
quotequote all
I'm posting this in the hope it may save someone else from having the same problem.

A couple of weeks ago I had a complete electrical failure on my 2000 Chim 450. 10:30 at night, 100 miles from home & lights, engine, the whole shooting match went off without warning. Got home at 6:00 the next morning on an AA relay truck. Not the best night I have spent, and the first time the Chim has let me down......

Check battery, good continuity to earth. 12.8v measured at the alternator, so main red battery lead to starter & 100A fuse are both OK. All the other electrics are dead, so time to pull the battery.....

On my car there are two wires from the +ve battery terminal. There's the fat red one which runs to the starter, but there's also a smaller doubled-up brown wire which I now know is the main power feed from the battery to the fuseboard at the very front of the footwell. Turns out there is an 80A fuse in this wire (circled in yellow on the pic and hidden behind the battery box) and the end of the fuseholder nearest the battery is well & truly melted. Eventually the fuse broke & cut off the power to the entire car. Probably a good job it did.....fibreglass cars burn quite enthusiastically I am told.

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So why did the fuseholder overheat & melt? It's in such a state it's hard to tell, but clearly the heat source was at the fuseholder terminal so there must have been a poor contact at that point. Maybe the nut holding the ring terminal was loose, or the ring terminal was poorly attached to the wire, or the wire itself corroded? Whatever, you can see the result here.....

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My advice? Get down in the footwell & have a good look at this wire, especially where the terminals are attached. Any doubts, replace. Access is b**** awful, but if this wire breaks or the fuse blows, everything stops. Trust me, I know!

Fortunately the damage was confined to what you can see in the photos and replacement of this and the associated wires was all that was needed for a full return to health. Interestingly, since replacing the wire the windows are faster, the cooling fans run faster, the warning lights are brighter and the boot now unlocks first time, every time. So there had been some signs, but it had been deteriorating gradually and I hadn't noticed.

This episode has clarified for me a couple of points regarding the electrical supply which I hadn't appreciated and which aren't clear from the owners handbook or the "Bible". First, the 80 A fuse in the passenger footwell carries the main power feed to the car and if this fails, you lose all the electrics including the hazard warning lights. (This is not good when you are stuck on an unlit country road at pub closing time...). Secondly, the 100A fuse on the chassis rail is in the alternator charging circuit, not the power supply to the car, so if this fails the car should continue to run but the battery will not be charged (can someone with more knowledge please confirm?).

Learn from your own mistakes, but better to learn from others'. Hope this helps.

loud430

550 posts

184 months

Wednesday 28th May 2014
quotequote all
hi, I had the same fuse go on my car, mine is an early one though & was a smaller type fuse but in the same place, luckily mine was just a build up of corrosion on the blades of the fuse but it took us ages to find it!

ukdj

1,004 posts

185 months

Wednesday 28th May 2014
quotequote all
I can confirm that the loss of the 100Amp fuse in the charging circuit will result in NO charge to the battery.

QBee

20,987 posts

145 months

Wednesday 28th May 2014
quotequote all
ukdj said:
I can confirm that the loss of the 100Amp fuse in the charging circuit will result in NO charge to the battery.
Had the 100 amp one happen twice in 12 months. Car dies when battery dies. You are correct. It is strapped under the car, driver's side, near where the rear arm of the front wishbone meets the chassis. Looks like the one in your pic.

The 80 amp is in the rats nest near the battery. Normally lying loose on top. Yours may have failed for lack of cooling, as you describe it as being in the narrow gap behind the battery. It is the first thing to check when you have a total electrical failure. I

2 sMoKiN bArReLs

30,255 posts

236 months

Wednesday 28th May 2014
quotequote all
I had that one conk out too....it did smell for a while before, but I still gummed up the traffic on Nottingham ring road. biggrin

kennybgr8

379 posts

143 months

Thursday 29th May 2014
quotequote all
Hi guys are the 80 and 100 fuses readily available off the shelf,,,

Thanks

blaze_away

1,510 posts

214 months

Thursday 29th May 2014
quotequote all
I have just been in my footwell and remade all the dodgy connections and relocated the battery to the boot. I also found the same Gize but that was in good order. I replaced the double brown wire with suitable heavy gauge single wire made up specifically for me with ring connections. Also had suitable main earth and starter wires custom made.

The footwell area is now clear organised and all relays. fuses etc are easy to check and see what's going on.

Parts spend was about 300 quid which was 140 for odessy battery 90 for cables and the rest on eyes, heat shrink, new fuses and holders etc. Well worth the effort in my view and passengers can now stretch their legs

QBee

20,987 posts

145 months

Thursday 29th May 2014
quotequote all
kennybgr8 said:
Hi guys are the 80 and 100 fuses readily available off the shelf,,,

Thanks
Yes, and it makes sense to fit midi fuses rather than the strip metal ones.

Sample Ebay source from searching on "midi fuse"

noisynorton

Original Poster:

18 posts

143 months

Thursday 29th May 2014
quotequote all
kennybgr8 said:
Hi guys are the 80 and 100 fuses readily available off the shelf,,,

Thanks
Got mine from Euro Car Parts. Not on the shelf at my local branch, but they had them by 3:00 pm the same day. http://www.eurocarparts.com/strip-fuses

I think QBee's right about the midi fuses and I'll swap mine out next time I'm in there. Euro don't seem to list these, but they are available here: http://www.vehicle-wiring-products.eu/VWP-onlinestore/fuses/fuses.php. I've used these guys for bike rewiring stuff and I've found them pretty good. They stock the fuseholders as well.

QBee

20,987 posts

145 months

Thursday 29th May 2014
quotequote all
The only advantage of the strip metal ones is that you can see if they are broken. But multimeter ownership is mandatory if you have a TVR..... smile

Sardonicus

18,962 posts

222 months

Thursday 29th May 2014
quotequote all
The only reason that as happened is because of high resistance on that circuit i.e resistance goes up voltage goes up to over come said resistance nerd probably nothing more than that 8mm nut being insufficiently tightened or poorly crimped terminal scratchchin IMO there is nothing wrong with those main fuse holders apart from the poor location of the one mounted underneath on the eng mount which is no fault of the unit itself frown when that one goes near the battery you loose st loads of electics eek put simply replace that holder assy and damaged cable and things we be well again wink





Edited by Sardonicus on Thursday 29th May 09:37

jojackson4

3,026 posts

138 months

Thursday 29th May 2014
quotequote all
My bets are the loose 8 mm nut

QBee

20,987 posts

145 months

Thursday 29th May 2014
quotequote all
Loose nuts can be blamed for most problems in society in the last 500 years... hehe

Richard 858

1,882 posts

136 months

Thursday 29th May 2014
quotequote all
And I thought you were "busy" with budgets / forecasts !!!hehe

ChimpOnGas

9,637 posts

180 months

Thursday 29th May 2014
quotequote all
noisynorton said:
I'm posting this in the hope it may save someone else from having the same problem.

A couple of weeks ago I had a complete electrical failure on my 2000 Chim 450. 10:30 at night, 100 miles from home & lights, engine, the whole shooting match went off without warning. Got home at 6:00 the next morning on an AA relay truck. Not the best night I have spent, and the first time the Chim has let me down......

Check battery, good continuity to earth. 12.8v measured at the alternator, so main red battery lead to starter & 100A fuse are both OK. All the other electrics are dead, so time to pull the battery.....

On my car there are two wires from the +ve battery terminal. There's the fat red one which runs to the starter, but there's also a smaller doubled-up brown wire which I now know is the main power feed from the battery to the fuseboard at the very front of the footwell. Turns out there is an 80A fuse in this wire (circled in yellow on the pic and hidden behind the battery box) and the end of the fuseholder nearest the battery is well & truly melted. Eventually the fuse broke & cut off the power to the entire car. Probably a good job it did.....fibreglass cars burn quite enthusiastically I am told.

[/URL]
[/URL]

So why did the fuseholder overheat & melt? It's in such a state it's hard to tell, but clearly the heat source was at the fuseholder terminal so there must have been a poor contact at that point. Maybe the nut holding the ring terminal was loose, or the ring terminal was poorly attached to the wire, or the wire itself corroded? Whatever, you can see the result here.....

[/URL]

My advice? Get down in the footwell & have a good look at this wire, especially where the terminals are attached. Any doubts, replace. Access is b**** awful, but if this wire breaks or the fuse blows, everything stops. Trust me, I know!

Fortunately the damage was confined to what you can see in the photos and replacement of this and the associated wires was all that was needed for a full return to health. Interestingly, since replacing the wire the windows are faster, the cooling fans run faster, the warning lights are brighter and the boot now unlocks first time, every time. So there had been some signs, but it had been deteriorating gradually and I hadn't noticed.

This episode has clarified for me a couple of points regarding the electrical supply which I hadn't appreciated and which aren't clear from the owners handbook or the "Bible". First, the 80 A fuse in the passenger footwell carries the main power feed to the car and if this fails, you lose all the electrics including the hazard warning lights. (This is not good when you are stuck on an unlit country road at pub closing time...). Secondly, the 100A fuse on the chassis rail is in the alternator charging circuit, not the power supply to the car, so if this fails the car should continue to run but the battery will not be charged (can someone with more knowledge please confirm?).

Learn from your own mistakes, but better to learn from others'. Hope this helps.
Nice write up noisynorton, your contribution demonstrates how the forum should be used.

I'm sure it'll prove helpful to many thumbup

Mr Stick

35 posts

135 months

Wednesday 11th June 2014
quotequote all
Hi I had exactly the same problem with my 2001 450 Chimp a month or so ago. Hacking down the outside lane of the M25 about a mile before the Dartford crossing and suddenly no electrics and engine in the fast lane, a little disconcerting to say the least, after a few expletives I managed to cut accross the other lanes and limped onto the hardshoulder. An hour and a half later and £100 poorer to the very nice tow truck man I was home again.
I checked the 100 amp fuse underneath and that was fine so eventually found the 80 amp fuse so thoughtfully tucked away behind the battery. The fuse holder was completely melted at one end and the 8mm nut was noticeably loose. Ahh I thought it's been arcing and has finally blown, the positive connection to the battery was also not particularly tight. The fuse holder and fuse were renewed and all connections tightened up ready for a test drive.
Since Iv'e had the car (approx 16 months) its suffered intermittently with the usual poor idling problems and didn't seem as quick as I thought it should be. Now however this was a different car, it pulled so smoothly and just kept accelerating through the gears causing much smirking and chuckling to myself, suddenly I was in love again with my Chimp. Sadly however after two more run outs the car is back to behaving like it did before, one minute idling at about 900 then surging to 1600 and falling back again, it feels slow and unresponsive too as before. Its had a new stepper motor recently and was serviced by a well known TVR guru.
Knowing how this car can go and how it goes now is bloody frustrating to say the least, any suggestions are welcome on what to do next.

ChimpOnGas

9,637 posts

180 months

Thursday 20th August 2020
quotequote all
Mr Stick said:
Hi I had exactly the same problem with my 2001 450 Chimp a month or so ago. Hacking down the outside lane of the M25 about a mile before the Dartford crossing and suddenly no electrics and engine in the fast lane, a little disconcerting to say the least, after a few expletives I managed to cut accross the other lanes and limped onto the hardshoulder. An hour and a half later and £100 poorer to the very nice tow truck man I was home again.
I checked the 100 amp fuse underneath and that was fine so eventually found the 80 amp fuse so thoughtfully tucked away behind the battery. The fuse holder was completely melted at one end and the 8mm nut was noticeably loose. Ahh I thought it's been arcing and has finally blown, the positive connection to the battery was also not particularly tight. The fuse holder and fuse were renewed and all connections tightened up ready for a test drive.
Since Iv'e had the car (approx 16 months) its suffered intermittently with the usual poor idling problems and didn't seem as quick as I thought it should be. Now however this was a different car, it pulled so smoothly and just kept accelerating through the gears causing much smirking and chuckling to myself, suddenly I was in love again with my Chimp. Sadly however after two more run outs the car is back to behaving like it did before, one minute idling at about 900 then surging to 1600 and falling back again, it feels slow and unresponsive too as before. Its had a new stepper motor recently and was serviced by a well known TVR guru.
Knowing how this car can go and how it goes now is bloody frustrating to say the least, any suggestions are welcome on what to do next.
Probably the greatest unanswered question of the TVR Chimaera forum scratchchin



Classic Chim

12,424 posts

150 months

Thursday 20th August 2020
quotequote all
ChimpOnGas said:
Mr Stick said:
Hi I had exactly the same problem with my 2001 450 Chimp a month or so ago. Hacking down the outside lane of the M25 about a mile before the Dartford crossing and suddenly no electrics and engine in the fast lane, a little disconcerting to say the least, after a few expletives I managed to cut accross the other lanes and limped onto the hardshoulder. An hour and a half later and £100 poorer to the very nice tow truck man I was home again.
I checked the 100 amp fuse underneath and that was fine so eventually found the 80 amp fuse so thoughtfully tucked away behind the battery. The fuse holder was completely melted at one end and the 8mm nut was noticeably loose. Ahh I thought it's been arcing and has finally blown, the positive connection to the battery was also not particularly tight. The fuse holder and fuse were renewed and all connections tightened up ready for a test drive.
Since Iv'e had the car (approx 16 months) its suffered intermittently with the usual poor idling problems and didn't seem as quick as I thought it should be. Now however this was a different car, it pulled so smoothly and just kept accelerating through the gears causing much smirking and chuckling to myself, suddenly I was in love again with my Chimp. Sadly however after two more run outs the car is back to behaving like it did before, one minute idling at about 900 then surging to 1600 and falling back again, it feels slow and unresponsive too as before. Its had a new stepper motor recently and was serviced by a well known TVR guru.
Knowing how this car can go and how it goes now is bloody frustrating to say the least, any suggestions are welcome on what to do next.
Probably the greatest unanswered question of the TVR Chimaera forum scratchchin

Replace the ecu rofl or piss about forever!
Rough running, a list about 20 long from extenders to caps to Ecu, temp sensors to confused ecu with out of step steppers biggrin
I remember my 450 running on 7 and I barely noticed it until putting my foot down a bit, decent ecu made it crisp as a bike engine. Removes a pile of connections and poor wiring, improves almost every aspect of engine management and gets the best out of Cams and intake mods etc.
These cars fit in between that space of what we would call a classic car so pretty damn basic and now not usuable in real terms other than a few run outs a year, Tvr are the real and only viable alternative to those very basic and often slow under powered cars.
The modern ecu simply puts the car into the 21st century,, useable and should get rid of a hat full of niggles that come with old fashioned electrics and ecu control.
I’ve not read this thread but it’s the obvious answer to me wink

ChimpOnGas

9,637 posts

180 months

Friday 21st August 2020
quotequote all
Classic Chim said:
Replace the ecu rofl or piss about forever!
Rough running, a list about 20 long from extenders to caps to Ecu, temp sensors to confused ecu with out of step steppers biggrin
I remember my 450 running on 7 and I barely noticed it until putting my foot down a bit, decent ecu made it crisp as a bike engine. Removes a pile of connections and poor wiring, improves almost every aspect of engine management and gets the best out of Cams and intake mods etc.
These cars fit in between that space of what we would call a classic car so pretty damn basic and now not usuable in real terms other than a few run outs a year, Tvr are the real and only viable alternative to those very basic and often slow under powered cars.
The modern ecu simply puts the car into the 21st century,, useable and should get rid of a hat full of niggles that come with old fashioned electrics and ecu control.
I’ve not read this thread but it’s the obvious answer to me
Agreed!

The truth is the improvements to your grounding and the rationalisation of the dreadful wiring TVR inflicted on every Chimaera were as influential, if not more influential, as the ECU upgrade itself Alun.

People suffering the 14CUX are likely often just suffering the way TVR wired the Lucas ECU and how the boys at Blackpool created all their critical grounds, there is much scope for considerable improvement in this department before the Lucas system is condemned itself.

I've discovered much, all of it clearly not understood by some who claim to be TVR specialists installing after market engine management systems, I've nearly concluded writing my report which one day I'll publicly publish online for all to see, what it'll reveal will be of great interest to every Chimaera owner for sure yes

Classic Chim

12,424 posts

150 months

Friday 21st August 2020
quotequote all
ChimpOnGas said:
Agreed!

The truth is the improvements to your grounding and the rationalisation of the dreadful wiring TVR inflicted on every Chimaera were as influential, if not more influential, as the ECU upgrade itself Alun.

People suffering the 14CUX are likely often just suffering the way TVR wired the Lucas ECU and how the boys at Blackpool created all their critical grounds, there is much scope for considerable improvement in this department before the Lucas system is condemned itself.

I've discovered much, all of it clearly not understood by some who claim to be TVR specialists installing after market engine management systems, I've nearly concluded writing my report which one day I'll publicly publish online for all to see, what it'll reveal will be of great interest to every Chimaera owner for sure yes
True but when you think of what it takes and the knowledge to put things right simply replacing the ecu and then associated poor wiring is just about a simple as tracing a Pile of looming issues. I think it’s the heat element that made me go the whole hog, the cux is ok but all them connections just screw up when hot. It’s one thing then another.

To think the single coil has to toll away on top the engine,, I feel sorry for em rofl
It’s just to much to ask in a way. Coil packs it’s all just better tech but well in line with the age and modern vibe that only Tvr offer in such a basic and still classically designed car.

My logic is, if I do another 50,000 miles in my Tvr I will have saved a lot of money on parts, services and tracing crap issues that can blight the cars.
It’s about peace of mind mostly then the added confidence to use the car, it’s extra power and cleaner delivery, it’s a no brainer with a long term project car I’d think if you want the most out of it as a useable daily everyday fun car. Mines a fair bit more economical overall too so a win win considering how big the bills are when chasing CUX faults and lost car down time I think it starts to feel like a bargain to have the car sorted and fast and reliable. ( stays in tune )
Sooner or later new ecu will have the odd fault but it should not be a wiring fault if it’s been done properly in my view. That should be good for a couple of decades at least imho.