Car died completely - help please
Discussion
The 80amp fuse in the footwell has to be the prime suspect.
The one mounted under the offside engine mount is only in the line between the alternator output and the live connection at the starter solenoid. If this one failed it would just mean you were no longer charging the battery which would progressively go flat.
Has anything got power? If so then tell us what and I will check the circuits to see if any other fuses could give the same symptoms.
Steve
The one mounted under the offside engine mount is only in the line between the alternator output and the live connection at the starter solenoid. If this one failed it would just mean you were no longer charging the battery which would progressively go flat.
Has anything got power? If so then tell us what and I will check the circuits to see if any other fuses could give the same symptoms.
Steve
Sorry, i did try to respond but i then lost internet as well, if the big black one in the footwell is from the battery and powers everything then thats the one, i have no radio, no cig lighter, and i cant even open the boot to get to any tools, spares or roof if it rains,
I had to resort to a recovery service who have now got me home so its battery out to try and access these fuses
I had to resort to a recovery service who have now got me home so its battery out to try and access these fuses
No need to remove the battery - just pull the wiring spaghetti onto the floor and look for the fuse in a black holder, often wrapped in tape. You may need to unbolt the fuse to see the break in it.
On my car, the fuse seems to sit above the right corner of the fuse board, in a length of wiring, but my battery has been transferred to the boot.
The other, simpler, explanation, would be a battery terminal has detached itself from the battery. It may have taken the 80 amp fuse with it, due to the big spark on the terminal detatching
On my car, the fuse seems to sit above the right corner of the fuse board, in a length of wiring, but my battery has been transferred to the boot.
The other, simpler, explanation, would be a battery terminal has detached itself from the battery. It may have taken the 80 amp fuse with it, due to the big spark on the terminal detatching
Edited by QBee on Sunday 3rd July 17:18
The battery terminals were fine, not do the big fuse, as you can see in the picture it hasn't cracked, it's blown.
Just to confirm is it's an 80 amp, do I get one from Halfords?, there isn't one of these in my standard box of spare fuses.
Is there any reason I can't replace this with something else like a circuit breaker so I can st least reset it rather than resorting to a recovery service, assuming there was a good reason for it blowing I guess I must have a major short somewhere, just surprised that one of the smaller fuses didn't blow first, or is this quite normal?
Just to confirm is it's an 80 amp, do I get one from Halfords?, there isn't one of these in my standard box of spare fuses.
Is there any reason I can't replace this with something else like a circuit breaker so I can st least reset it rather than resorting to a recovery service, assuming there was a good reason for it blowing I guess I must have a major short somewhere, just surprised that one of the smaller fuses didn't blow first, or is this quite normal?
The one in the footwell is 80amp. The one on the engine mount is 100amp.
As you say you do not know yet why it failed. It may have fractured which would then apear to be a burn when it tried to take load.
Yes you could use a circuit breaker.
Steve
As you say you do not know yet why it failed. It may have fractured which would then apear to be a burn when it tried to take load.
Yes you could use a circuit breaker.
Steve
Edited by Steve_D on Sunday 3rd July 18:16
That looks a fair old short to me, need to investigate what it feeds altogether first.
Ive been thinking about putting one of these in.
https://www.amazon.co.uk/Protection-Audio-Inline-C...
Ive been thinking about putting one of these in.
https://www.amazon.co.uk/Protection-Audio-Inline-C...
Edited by Belle427 on Sunday 3rd July 18:55
That circuit breaker looks interesting, just need to find out why its called an audio cb.
Does anyone have a circuit diagram going from the 80A fuse out so i can start testing?
If i disconnect the ecu would it be ok to use a Mega to look for shorts?
The other thing i did notice that just before cutting out completely i was having a bad misfire session, the lights i have set up to monitor circuits showed me that i was loosing the earth connection to the pump relay, if i get lucky the blown fuse might be linked to all my other hiccup, misfire, cut out problems
Paul
Does anyone have a circuit diagram going from the 80A fuse out so i can start testing?
If i disconnect the ecu would it be ok to use a Mega to look for shorts?
The other thing i did notice that just before cutting out completely i was having a bad misfire session, the lights i have set up to monitor circuits showed me that i was loosing the earth connection to the pump relay, if i get lucky the blown fuse might be linked to all my other hiccup, misfire, cut out problems
Paul
Dont use a megger or you will blow any other sensitive circuits, a basic multimeter will find shorts.
I would trace those large cables by hand, the wiring diagrams are sketchy at best.
I would guess at the large cable going to the fusebox, not sure on the 2 reds.
Are you sure it didnt just short to the battery negative terminal where it sits?
I would trace those large cables by hand, the wiring diagrams are sketchy at best.
I would guess at the large cable going to the fusebox, not sure on the 2 reds.
Are you sure it didnt just short to the battery negative terminal where it sits?
My local TVR garage always change these fuses at service time regarding them as a service item.
They do tend over time to start cracking in the centre and weakening so will then not handle much current before blowing, while its worth checking to see if any short circuits caused the failure dont be surprised if everything checks OK.
They do tend over time to start cracking in the centre and weakening so will then not handle much current before blowing, while its worth checking to see if any short circuits caused the failure dont be surprised if everything checks OK.
The battery positive terminal has a rubber mat over it, so its not that.
When i first put a meter on the positive to negative i only had 100 ohm, but now i am at infinity, i have removed all the insulation and protective covers thinking i would find the culprit in the loom, but no luck yet, more wriggling around until i get a short again i guess.
My next question is how do i access the boot and tools if this ever happens again?
Paul
When i first put a meter on the positive to negative i only had 100 ohm, but now i am at infinity, i have removed all the insulation and protective covers thinking i would find the culprit in the loom, but no luck yet, more wriggling around until i get a short again i guess.
My next question is how do i access the boot and tools if this ever happens again?
Paul
Paulprior said:
The battery positive terminal has a rubber mat over it, so its not that.
When i first put a meter on the positive to negative i only had 100 ohm, but now i am at infinity, i have removed all the insulation and protective covers thinking i would find the culprit in the loom, but no luck yet, more wriggling around until i get a short again i guess.
My next question is how do i access the boot and tools if this ever happens again?
Paul
The 80amp fuse serves all the electrics in the fusebox so the problem (if it truly exists) could be anywhere.When i first put a meter on the positive to negative i only had 100 ohm, but now i am at infinity, i have removed all the insulation and protective covers thinking i would find the culprit in the loom, but no luck yet, more wriggling around until i get a short again i guess.
My next question is how do i access the boot and tools if this ever happens again?
Paul
You could start by just rigging a normal 25amp fuse across and see what happens. This fuse should handle any circuit if you test them one at a time.
See my PM regarding the boot.
Steve
Thanks guys for the info, i will have a practice today
I spent a few hours trying to track a short, i was confident i would find it in the loom, but to have a problem like that i would need two damaged cables touching each other, i cannot find anything visual and i still measure infinity on the meter, but i havent done anything apart from moving cables around in the footwell, very frustrating
I spent a few hours trying to track a short, i was confident i would find it in the loom, but to have a problem like that i would need two damaged cables touching each other, i cannot find anything visual and i still measure infinity on the meter, but i havent done anything apart from moving cables around in the footwell, very frustrating
Reference fitting a circuit breaker (I'm not a the person and don't own one but this is just info) is it a normal blow or fast blow fuse fitted. You might want to look at the action time for the circuit breaker. If it's too slow you could damage the circuit before the circuit breaker has time to open. Maybe look to see if you can find the fuse specification and make sure the circuit breaker is as fast or faster.
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