Transmission Tunnel Earthing Point
Discussion
Evening all,
I have been having some electrical problems with the car for a while that have steadily got worse..I have been hunting them down for a while and have been changing components but to no avail.
Anyhoo I moved the car out of the garage a couple of weekends ago whilst I was tidying it out. I had taken the negative cable of the battery as I do to try and prolong the charge. A couple of days later I went to put the car in and I put the cable back and went to start the car...It started playing up by making a clicking noise (relays) and total power failure...whilst wiggling the earth lead I could hear the relays jump back into life and lights on the dash. Turn the key and click, you guessed it total power loss...after a few minutes the engine started a couple of times but basically died straight away...each time I would have to jump into the passenger foot well and wiggle the lead again.
In the end the car started and it was fine whilst I moved it back into the garage...I went to take the negative lead off the battery and could not believe how hot it was, I mean it was burning my hand. So I have started to trace the cable back to its earthing point...Oh what joy...
I have basically ripped out my dash and centre console and finally located the Left and Right earthing points which are hidden under the transmission tunnel plasti cover. I can see them with a torch and they both look like they are tightly screwed and are not rusted at all.
It looks like the only way I am going to get to it is by ripping up all the old carpet under the dash, is this right?
Another alternative is can I rewire to a new earthing point for the main Battery negative cable? Does anyone know what (if any) other cables will be earthed to the left hand side (sitting inside car) earthing point so that I can rewire these too.
As always any help appreciated.
Deano
I have been having some electrical problems with the car for a while that have steadily got worse..I have been hunting them down for a while and have been changing components but to no avail.
Anyhoo I moved the car out of the garage a couple of weekends ago whilst I was tidying it out. I had taken the negative cable of the battery as I do to try and prolong the charge. A couple of days later I went to put the car in and I put the cable back and went to start the car...It started playing up by making a clicking noise (relays) and total power failure...whilst wiggling the earth lead I could hear the relays jump back into life and lights on the dash. Turn the key and click, you guessed it total power loss...after a few minutes the engine started a couple of times but basically died straight away...each time I would have to jump into the passenger foot well and wiggle the lead again.
In the end the car started and it was fine whilst I moved it back into the garage...I went to take the negative lead off the battery and could not believe how hot it was, I mean it was burning my hand. So I have started to trace the cable back to its earthing point...Oh what joy...
I have basically ripped out my dash and centre console and finally located the Left and Right earthing points which are hidden under the transmission tunnel plasti cover. I can see them with a torch and they both look like they are tightly screwed and are not rusted at all.
It looks like the only way I am going to get to it is by ripping up all the old carpet under the dash, is this right?
Another alternative is can I rewire to a new earthing point for the main Battery negative cable? Does anyone know what (if any) other cables will be earthed to the left hand side (sitting inside car) earthing point so that I can rewire these too.
As always any help appreciated.
Deano
Edited by Deano 4.0 Chimp on Saturday 17th May 19:28
Hi Deano,
you said "I went to take the negative lead off the battery and could not believe how hot it was, I mean it was burning my hand."
This would indicate that the poor connection is at the battery rather than at the earth point, an electrical joint will only get hot if it goes high resistance thus causing the large temperature rise.
Before you get involved in ripping any more carpet out & running new cables, I would give the battery terminal and the connector on the cable a really good clean, use wire wool or similar, get both parts really bright clean, then put a heavy load on the circuit, eg headlights & fog light and see if it gets hot still. If you have access to a voltmeter measure the voltage between the battery negative and a good earth point eg somewhere on the engine, you should measure only a very low voltage, say 0.1 V or less with this sort of load switched on any more then this and you have a poor earth connection somewhere that will need looking into further.
Good luck
Andy
you said "I went to take the negative lead off the battery and could not believe how hot it was, I mean it was burning my hand."
This would indicate that the poor connection is at the battery rather than at the earth point, an electrical joint will only get hot if it goes high resistance thus causing the large temperature rise.
Before you get involved in ripping any more carpet out & running new cables, I would give the battery terminal and the connector on the cable a really good clean, use wire wool or similar, get both parts really bright clean, then put a heavy load on the circuit, eg headlights & fog light and see if it gets hot still. If you have access to a voltmeter measure the voltage between the battery negative and a good earth point eg somewhere on the engine, you should measure only a very low voltage, say 0.1 V or less with this sort of load switched on any more then this and you have a poor earth connection somewhere that will need looking into further.
Good luck
Andy
lotusandy said:
This would indicate that the poor connection is at the battery rather than at the earth point, an electrical joint will only get hot if it goes high resistance thus causing the large temperature rise.
Before you get involved in ripping any more carpet out & running new cables, I would give the battery terminal and the connector on the cable a really good clean, use wire wool or similar, get both parts really bright clean, then put a heavy load on the circuit, eg headlights & fog light and see if it gets hot still.
Before you get involved in ripping any more carpet out & running new cables, I would give the battery terminal and the connector on the cable a really good clean, use wire wool or similar, get both parts really bright clean, then put a heavy load on the circuit, eg headlights & fog light and see if it gets hot still.
Sorry its been a while but thought I would update this post in the hope t may help others...
A big thanks to Lotusandy
cleaned up everthing to an inch of its life including battery terminals and put on new washers on the outside of the box lid (if ya know what I mean).
Car now starts with no problems at all now...
A few issues with my oil pressure and water temp dials but thats another post..
Many thanks..
Deano
A big thanks to Lotusandy
cleaned up everthing to an inch of its life including battery terminals and put on new washers on the outside of the box lid (if ya know what I mean).Car now starts with no problems at all now...
A few issues with my oil pressure and water temp dials but thats another post..
Many thanks..
Deano
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