Electrical problem please help
20 December 2009, 05:08 PM
#1
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
Electrical problem please help
Hello all
.
Yet another chapter to this cars line of problems
.
Car will run fine but as soon as you put your foot down (put on boost) the main fuse will blow. The car starts to judder, then pop. Its the fuse box in engine bay, centre of the three 45amp fuses. If you drive the car like an old granny it seem's to be ok in the main, although it did blow once at low speed. No electrical componants have been changed recently and I have checked all round the engine for loose/broken or chafed wires. Any help would be appreciated, as I have only just got this car back on the road and its sending me round the bend
.
Cheers
Del
.Yet another chapter to this cars line of problems
.Car will run fine but as soon as you put your foot down (put on boost) the main fuse will blow. The car starts to judder, then pop. Its the fuse box in engine bay, centre of the three 45amp fuses. If you drive the car like an old granny it seem's to be ok in the main, although it did blow once at low speed. No electrical componants have been changed recently and I have checked all round the engine for loose/broken or chafed wires. Any help would be appreciated, as I have only just got this car back on the road and its sending me round the bend
.Cheers
Del
20 December 2009, 05:48 PM
#3
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
20 December 2009, 08:50 PM
#5
20 December 2009, 09:15 PM
#6
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
Hello Simon, hope you are well. Have run a seperate earth lead from battery to block and still the same. Voltage on the battery terminals are 13.7v off and 14.1 running.
20 December 2009, 09:33 PM
#7
Scooby Regular
Join Date: Mar 2008
Posts: 355
Likes: 0
Received 0 Likes
on
0 Posts
if its blowing a 45a thats quite a short somewhere. Unfortunately it may be a case of stripping off some of the black tape on parts of loom and looking for short, had to do this on a granvia last week but got lucky and found it by the diesel pump almost straight away. Did have a wiring diagram on disc but cant find it, seem to remember one of those fuses being the fuel pump. Strange that it does it under load but weird things can happen with wiring faults!
Trending Topics
21 December 2009, 10:46 PM
#11
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
22 December 2009, 08:19 PM
#14
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
22 December 2009, 08:22 PM
#15
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
22 December 2009, 10:15 PM
#16
Scooby Regular
iTrader: (18)
Join Date: Jul 2007
Location: Guildford Surrey
Posts: 693
Likes: 0
Received 0 Likes
on
0 Posts
Have you identified exactly what the fuse controls ie:which wires and circuits are associated with the fuse?
I somehow doubt the battery or the altenator is at fault from what i have read, so the following is just basic checks as you have done.
Have you checked the bolted connector/terminal under the fuse box in the engine bay ie: clean and dry?
Although the altenator is charging, have you checked that the altenator belt is tight?
If you test the voltage of the battery immediately after turning the engine off, the voltage in the battery will be as high as 13.7V very easily, If you want to get a true reading from the battery do it in the morning before you start the car, as the battery will have had a couple of hours to stabilise.
The trip out(maximum voltage) for the altenator will be 14.4V but no higher than that, but as you say check it while driving as you might be getting a voltage spike.
You also need to check what the amperage is at maximum charge voltage with and without the loads on (lights, fans,etc). You will need an amp guage to test this, which you most likely wont have.
I somehow doubt the battery or the altenator is at fault from what i have read, so the following is just basic checks as you have done.
Have you checked the bolted connector/terminal under the fuse box in the engine bay ie: clean and dry?
Although the altenator is charging, have you checked that the altenator belt is tight?
If you test the voltage of the battery immediately after turning the engine off, the voltage in the battery will be as high as 13.7V very easily, If you want to get a true reading from the battery do it in the morning before you start the car, as the battery will have had a couple of hours to stabilise.
The trip out(maximum voltage) for the altenator will be 14.4V but no higher than that, but as you say check it while driving as you might be getting a voltage spike.
You also need to check what the amperage is at maximum charge voltage with and without the loads on (lights, fans,etc). You will need an amp guage to test this, which you most likely wont have.
23 December 2009, 07:40 PM
#17
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
Have you identified exactly what the fuse controls ie:which wires and circuits are associated with the fuse?
I somehow doubt the battery or the altenator is at fault from what i have read, so the following is just basic checks as you have done.
Have you checked the bolted connector/terminal under the fuse box in the engine bay ie: clean and dry?
Although the altenator is charging, have you checked that the altenator belt is tight?
If you test the voltage of the battery immediately after turning the engine off, the voltage in the battery will be as high as 13.7V very easily, If you want to get a true reading from the battery do it in the morning before you start the car, as the battery will have had a couple of hours to stabilise.
The trip out(maximum voltage) for the altenator will be 14.4V but no higher than that, but as you say check it while driving as you might be getting a voltage spike.
You also need to check what the amperage is at maximum charge voltage with and without the loads on (lights, fans,etc). You will need an amp guage to test this, which you most likely wont have.
I somehow doubt the battery or the altenator is at fault from what i have read, so the following is just basic checks as you have done.
Have you checked the bolted connector/terminal under the fuse box in the engine bay ie: clean and dry?
Although the altenator is charging, have you checked that the altenator belt is tight?
If you test the voltage of the battery immediately after turning the engine off, the voltage in the battery will be as high as 13.7V very easily, If you want to get a true reading from the battery do it in the morning before you start the car, as the battery will have had a couple of hours to stabilise.
The trip out(maximum voltage) for the altenator will be 14.4V but no higher than that, but as you say check it while driving as you might be getting a voltage spike.
You also need to check what the amperage is at maximum charge voltage with and without the loads on (lights, fans,etc). You will need an amp guage to test this, which you most likely wont have.
Checked wires going to fuse box and all seem ok.
HOWEVER A CONFESSION FROM MY SON!!!!!!!!!!!!!!!!!!!!!
He used my car while I was at work to jump start his mates car. They connected both leads to the other car and then when connecting to mine, which was running apparenly, they put them on the wrong terminals.
Apart from the alternator is the anything else in the charging circuit, that controls the amount of power output??? and what other damage is possible?
Cheers
Del
23 December 2009, 09:25 PM
#19
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
26 December 2009, 07:50 PM
#20
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
Still doing it
Changed alternator today for a known good one and the problem persists.
Drove the car for around 5 miles gently with no problem, as soon as i put my foot down (in second about half throttle) pop fuse gone again.
Any mor ideas?
Drove the car for around 5 miles gently with no problem, as soon as i put my foot down (in second about half throttle) pop fuse gone again.
Any mor ideas?
26 December 2009, 08:23 PM
#21
Scooby Regular
iTrader: (2)
Join Date: Jan 2004
Location: Hertfordshire
Posts: 4,312
Likes: 0
Received 0 Likes
on
0 Posts
I suspect a main live has melted> posibly the starter cable> and as your accelerating the engine rock is causing it to short to earth.
I suspect accelerating hard in any gear will cause this.
Check all the main live feeds to starter fuse box etc< check theres nothing bare and nothing able to eath out.
I suspect accelerating hard in any gear will cause this.
Check all the main live feeds to starter fuse box etc< check theres nothing bare and nothing able to eath out.
27 December 2009, 12:24 AM
#22
Scooby Regular
Join Date: Mar 2008
Posts: 355
Likes: 0
Received 0 Likes
on
0 Posts
27 December 2009, 10:37 AM
#23
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
27 December 2009, 12:47 PM
#24
Scooby Regular
Join Date: Mar 2008
Posts: 355
Likes: 0
Received 0 Likes
on
0 Posts
shame your not a bit closer, love finding electrical faults! try moving the loom around where you can to simulate engine moving to see if you can get the fuse to blow which would narrow down a problem in the loom. it goes right across the front from fuse box under bonnet to drivers side inner wing then into car. When mine melted at front due to headers it did some weird and wonderful things! does it do it everytime you boot it? does it do it if you rev high but slowly if you see what i mean?
29 December 2009, 08:16 PM
#26
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
Been all over the car. checked wires, none bare/earthing out that I can see. With engine running at idle car is fine. Moving all wires fuse still intact. Take revs up to around 5.5-6k still no probs. Back at idle, handbrake on, select first gear and rock the engine, fuse still intact. As soon as I drive it and boot it pop it goes. Drive normal keeping under 3k and shes fine.
If I didn't know better I would have thought that there was a camera filming me somewhere as this is getting rediculous.
If I didn't know better I would have thought that there was a camera filming me somewhere as this is getting rediculous.
Last edited by mcvicar; 29 December 2009 at 08:17 PM.
30 December 2009, 06:36 PM
#29
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts
30 December 2009, 06:37 PM
#30
Scooby Regular
Thread Starter
Join Date: Aug 2005
Location: Surrey
Posts: 503
Likes: 0
Received 0 Likes
on
0 Posts