Duff Battery????

w44nty

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My battery on my ML has been a bit weak whilst starting over the last week or 2.

This morning when I went to start,it turned once and then died,when I turn the key nothing happens but the headlights come on,is this the sign that i need a new battery or could it be something else

Thanks Steve
 

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It does look as though the battery has passed its sell by date, ideally you would put a voltmeter over the battery when cranking, I presume it just makes a click when you try and start now.

The first cold spell brings out the poor batteries

Do you have a volt meter
 

Naraic

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Headlights on...must mean something else. Possibly a bad main earth. Usually when a battery dies...things don't just come on by themselves.
 
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w44nty

w44nty

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Headlights on...must mean something else. Possibly a bad main earth. Usually when a battery dies...things don't just come on by themselves.


They come on when key is turned in the ignition,it do not normally do that
 
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It does look as though the battery has passed its sell by date, ideally you would put a voltmeter over the battery when cranking, I presume it just makes a click when you try and start now.

The first cold spell brings out the poor batteries

Do you have a volt meter

Yes Malcolm just a click and the headlights come on,the battery has been noticably weak on starting in mornings over the last few weeks,its been ok during the day whilst in use,it just gave up this morning after 1 turn
 

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They come on when key is turned in the ignition,it do not normally do that

That's very strange...so the light switch is off...but the lights come on?
 

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Headlights on...must mean something else. Possibly a bad main earth. Usually when a battery dies...things don't just come on by themselves.

Not on modern cars where a relay is used to operate the starter, the voltage can be high enough to allow the lamps to light but not enough to close that relay. A check with a voltmeter is the first thing to do.


But as it is an ML we know that they get bad earth wires on the engine, there are many post here on this.

One could prove this by using a jumper lead from the engine to a good ground point on the body
 

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Yes Malcolm just a click and the headlights come on,the battery has been noticably weak on starting in mornings over the last few weeks,its been ok during the day whilst in use,it just gave up this morning after 1 turn

Niaracs post reminded me of the earth wire problems on an ML, do what I said in my above post
 

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Not on modern cars where a relay is used to operate the starter, the voltage can be high enough to allow the lamps to light but not enough to close that relay. A check with a voltmeter is the first thing to do.


But as it is an ML we know that they get bad earth wires on the engine, there are many post here on this.

One could prove this by using a jumper lead from the engine to a good ground point on the body

The way I read it...the lights are coming on, but they are not switched on...waiting for confirmation.
 
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w44nty

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That's very strange...so the light switch is off...but the lights come on?

Yes it seems very strange to me,when my son comes home I will try to jump start it ,if it do ,I would hopefully presume the battery has had it.
 

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Yes it seems very strange to me,when my son comes home I will try to jump start it ,if it do ,I would hopefully presume the battery has had it.

No, don't presume that...look for the reason the lights are coming on...as above, we think bad earth.
 
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The way I read it...the lights are coming on, but they are not switched on...waiting for confirmation.
Yes that is exactly what is happening,all the lights come on on the dash,glow plug goes out,turn key no engine turning ,just a click and headlights light up without being turned on or in auto mode
 

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Yes it seems very strange to me,when my son comes home I will try to jump start it ,if it do ,I would hopefully presume the battery has had it.

If it starts from a jump over the battery, then battery,,but why not put the jump lead on a clean part of the engine and to a good chassis or body point and try
 
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w44nty

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No, don't presume that...look for the reason the lights are coming on...as above, we think bad earth.

Just been out and looked at battery,there have been some water around the earth terminal caused by the wet weather ,would this cause a bad earth connection
 
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w44nty

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If it starts from a jump over the battery, then battery,,but why not put the jump lead on a clean part of the engine and to a good chassis or body point and try
When my son comes home malcolm I will try out,do I just put one lead on the engine and the other end on the chassis and just try to start as normal,I take it then if it starts its a bad earth
 

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I was thinking while eating that the lights could come on as it could be trying to find a ground point,,I am 100% sure it is that wire, its been deteriorating this last new days and no gone completely
 

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The battery in my ML just died overnight about a month ago - it would power lights, windows etc but not enough to turn the starter. New battery installed, had to reset radio code and that was it. Gearchanges (auto) a lot smoother as it obviously erased the memory in the box and went back to factory settings.
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w44nty

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If it starts from a jump over the battery, then battery,,but why not put the jump lead on a clean part of the engine and to a good chassis or body point and try


Update:

Car started with Jump Start,drive to my local garage they tested battery it was kaput.

Fitted new Bosch battery everything ok now,so it was the battery after all(fingers and everything else crossed),wallet now £80 lighter.

Thanks everyone for your imput and help

Steve
 

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Update:

Car started with Jump Start,drive to my local garage they tested battery it was kaput.

Fitted new Bosch battery everything ok now,so it was the battery after all(fingers and everything else crossed),wallet now £80 lighter.

Thanks everyone for your imput and help

Steve

So I got it right in my first post :D So pleased you are OK
 


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