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Little Megger
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Discussion Starter · #1 ·
My Mondeo developed a dpf fault today, I also noticed that the alternator is only charging at 13.7 volts. I'm wondering if it's linked, I thought the alternator either charges or doesn't. With the engine off the voltage is about 12.7v, which is what I'd expect. Could a fault alternator cause othe issues with sensors that are looking for a certain voltage?
 

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My Mondeo developed a dpf fault today,
1 I also noticed that the alternator is only charging at 13.7 volts.
2 I'm wondering if it's linked,
3I thought the alternator either charges or doesn't.
4 With the engine off the voltage is about 12.7v, which is what I'd expect.
5 Could a fault alternator cause othe issues with sensors that are looking for a certain voltage?
1. How did you notice, from where did you get the reading

2. I don't think it likely

3 Modern cars are more complicated, alternator output is governed for optimum fuel/emissions efficiency

4 Depending upon when and with what the reading was attained that sounds like a good battery

5 Someone else may have a different view but at 12.7v i would think no.



Have you established what the DPF fault code was?
 

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Little Megger
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Discussion Starter · #3 ·
I've got a gauge in the car, but also checked at the battery with a multimeter, radio and aircon were running when I took the reading. Battery is only a year old (Bosch) as had to change during lockdown. DPF fault, looks like the sensor, I replaced the DPF, Lamba sensor and pipes about 2 years ago, so only thing left is the sensor. Hopefully I can get one soon as it's currently in limp mode and un-useable.
 

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13.7v is about right for charging, what was you expecting, regarding dpf the only issue you can really get are that its blocked with ash and you end up with dpf differntial pressure faults
 

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Little Megger
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Discussion Starter · #5 ·
So the DPF sensor arrived today, the cars been sat since last Thursday and the battery was down to 2 volts, like something has been draining it, I'm hoping it's the faulty sensor otherwise, no idea where to start.
 

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Clever Clauggs
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Charge battery overnight and after its been stood for half a day take reading ,most alternators give out 14.4v whilst revving engine.my 2002 mondeo only puts out 13.8v as i think smart charge is not working.
 

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Fitted a new Bosch S5 to my car but I think I got a dud one. First battery in years that actually needed
charging from new. Still gave a low battery warning when sitting in the car with the radio on.

Replaced with a Yuasa battery and no more battery issues.
 

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So the DPF sensor arrived today, the cars been sat since last Thursday and the battery was down to 2 volts, like something has been draining it, I'm hoping it's the faulty sensor otherwise, no idea where to start.
1st thing, if the battery is more than 5 years old then change it, as you could just be chasing a dud battery issue
 

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Little Megger
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Discussion Starter · #9 ·
As mentioned earlier Battery was changed last year, Bosch Silver.

Sent from my SM-G998B using Tapatalk
 

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As mentioned earlier Battery was changed last year, Bosch Silver.

Sent from my SM-G998B using Tapatalk
if your battery is down to 2v then its definatly knackered now, 12v is considered flat, 2v would be dead and not recoverable, under warrenty get it swapped out
 
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