Battery light on.

Soldato
Joined
9 Sep 2008
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Glasgow
Morning.

Late last night i came out, started the car to defrost it/heat it as i have a baby on board was around -2, i left my headlights on, radio on and heated front and rear heated windscreen, fans etc and jumped back into the house for 10mins

When i came back out the window heaters had went off and the battery light had came on.

I had an issue 4 months ago with the battery light coming on and had a brand new alternator fitted and it had been fine since.

Would this be a battery issue? The car started fine though.

55 plate mondeo tdci 2.0.

Cheers
 
Soldato
Joined
5 Oct 2009
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Spalding, Lincs
All that electrical load on at once will be a huge current draw. If you do an alternator test on a healthy alternator and battery at idle, it will likely fail the test as they can't keep up with the current draw at idle, with the front heated screen on as that's the biggest power draw.

If you do have a poor battery then it most definitely wont help at all.
 
Associate
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20 Aug 2008
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Stafford
The alternator needs to be spinning at a certain RPM to start charging when you start the car. With all that current draw and if the engine hiccups the charging may cut off and not start again intill the initial RPM is met by the alternator again. His the light remained on or did it go out when you revved the engine?
 
Soldato
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The thing that got me here was that you left the car ALONE to warm up whilst turned on!

Do you actually want to have it stolen?
 
Soldato
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UK
Mk3 Mondeo TDCi's have some sort of electric aux heater built in that comes on below certain temperatures which i believe is a bit like a glow plug. That along with all the above will have been drawing some epic current.

If it's the original Motorcraft battery it'll have a first charged date stamped on it.
 
Associate
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The thing that got me here was that you left the car ALONE to warm up whilst turned on!

Do you actually want to have it stolen?

Wasn't going to mention it as seems common practice for most nowadays even though makers say start the car and drive away. Insurance do not pay out if the car is taken either when left like that.
 
Soldato
Joined
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West sussex
The thing that got me here was that you left the car ALONE to warm up whilst turned on!

Do you actually want to have it stolen?
Depending on location, I'd never leave my car alone in London where I lived.. but where I live now there's not a soul awake or anywhere near my car..
 
Soldato
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S.E Wales
Always let my car warm up while I go eat my breakfast, It's on my driveway, it's not going anywhere....TBF I do live in a more remote side of my town where the street consists more of the older generation.
 
Soldato
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North Wales
It really depends where you live, i do it any day its been frosty as i have a big driveway where you can't really see the cars from the road and we also live in the middle of nowhere.

If i was living in the center of Manchester i doubt i'd do it :p
 
Soldato
Joined
13 Jan 2003
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23,628
A little fact on the focus TDCI that may apply to the Mondeo too - there are two alternators you can get (the cheap one and the more expensive part) for the titanium trim with all the gadgets etc I needed the higher power one but the first replacement they used the cheap one. I found that out when I fitted the second one myself and the cat seemed far more with it (faster charging etc).

The battery and alternator seem to kill each other off if one dies, so you may as well replace the battery if the alternator is putting out enough power (iirc it was 15V or so across the battery terminals). Measuring current is far more difficult (needing a clamp meter).

Hmm not sure about an aux heater - perhaps in cold climates (Norway for example) but the ford front window that has a heating matrix in it sucks power - same as the heated seats and the air heater matrix.

In Norway they have a remote for starting and warming up the car from the house :)
 
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