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Bad Earth From Battery


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#1 chris2009

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Posted 04 January 2010 - 11:04 PM

Mini wouldn't start once again this morning took the battery tester to my battery and it said less than 20% :) As it took my battery out i noticed that my earthing cable was very badly worn were it had been moved around so much. Now i now that can cause bad current flow to all the earths in the car does that mean that the electrics aren't getting as much power as they should be? Any reccomendations on wire thickness to use?

#2 Sherlock

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Posted 05 January 2010 - 12:54 AM

If you look at the thickness of the large wire which goes to your starter motor, that's the kind of thickness you need, most motor factors supply earth leads in various lengths which will be adequate for the job.

#3 Dan

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Posted 05 January 2010 - 01:14 AM

As above, just buy a pre-made earth cable. They are available everywhere and only cost a few quid. Making one will be more hassle than it's worth by a long way.

#4 Bungle

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Posted 05 January 2010 - 07:59 AM

even halfords sell them

#5 chris2009

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Posted 05 January 2010 - 05:55 PM

Cheers guys. Just to confirm would that be any contribution to why my car wont start as in nothing can earth properly so not causing enough spark in the plugs to get going?

#6 chris2009

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Posted 07 January 2010 - 07:11 PM

Anyone help me with this one?

#7 danie garry

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Posted 07 January 2010 - 08:09 PM

yes a poor earth would make it hard to start the car

#8 chris2009

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Posted 08 January 2010 - 02:08 PM

Cheers buddy finnaly someone replied

#9 Minigirl

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Posted 08 January 2010 - 02:20 PM

did you get your problem fixed? were in a pretty similar situation - having to jump start the car every time i want to go out :lol:

see here http://www.theminifo...p;#entry1691532 and http://www.theminifo...p;#entry1684098

#10 ahmacc

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Posted 08 January 2010 - 03:07 PM

The effectiveness of the earth strap can affect whether or not the car starts (or any poor earth connection) but your starting problem was probably the low battery level. If you jump started the car by connecting jump leads to the battery terminals then you'd be using the same earth strap and earth connections so they would have been good enough. One way to check is by using the jump leads from the battery negative terminal to somewhere on the engine (alternator bracket for example) - if it starts with that extra earth then the earth strap (or connections) are at fault - if it still doesn't then its the battery or something else.

#11 bmcecosse

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Posted 08 January 2010 - 04:15 PM

The main problem was the flat battery - but you need to find out WHY it was flat ? Good earth strap is essential - so just get a new one anyway!

#12 finch661

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Posted 08 January 2010 - 04:27 PM

i am having the same issue as minigirl. i charge my battery up. and after a couple of days (of not using it) it wont start! my car is in at my local mini man atm, and he thinks he has found the problem. my earth (engine to body) was a bit lose. we shall see if this is the cause :lol:

#13 R1minimagic

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Posted 08 January 2010 - 04:35 PM

Why would an earth strap give a problem every 2 days?!!

Sounds just like lack of use and cold weather to me. If you only do short journeys the battery is never going to charge no matter how good your system is.

It takes a lot of current to start a car, so you need to get that back by driving a certain distance to recharge the battery.

If you cant/dont drive far enough good idea to get a trickle charger for about £5.

#14 chris2009

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Posted 08 January 2010 - 05:23 PM

Well i managed to get a new battery and new earthing cable from the battery and still no luck with it starting. Even when i tried to jump start it i put the -ve lead on an unpainted bit of the body and still didn't start. Still didn't start with 4 of us running like mainacs down my road trying to bump start it. Checked all the plugs for spark whilst cranking it and each one sparked. Any other ideas guys coming to my wits end!!

#15 R1minimagic

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Posted 08 January 2010 - 05:30 PM

So it's either a fueling or a timing issue.

If you pull a plug out is it wet or dry?

You could take one plug out and take the coil HT lead off so it can't start, turn the engine over on the starter, does fuel mist come out of the spark plug hole?

Could be a bit of carb icing and you are not getting any fuel through..

Edited by R1minimagic, 08 January 2010 - 05:31 PM.





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