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Technical battery light

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Technical battery light

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confuszd

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Hi you fellow fiat fanatics. Many thanks in advance to anyone who can offer any advice. Along with my Fiat 500, which be my fun work runaround, last year, I treated myself to a 2007 fiat ducato Adria mobil, which was also lots of fun until it wasn't. First there was the windscreen wiper motor and the bottle wash motor, but hey they were easyish to get to and replace. Not to much brain damage.
On our next trip away, we broke down (twice)owing to what now seems to have been an alternator issue - replacing it was a horrid job, but the battery be once again charging, which be a huge relief, however that pesky red battery might be still there taunting me on the dashboard as it has been for months (kind of ignored it until the alternator died), but am bit concerned if I continue to ignore it, it might cause more problems.
So any ideas???
I have checked all those earths and fuses, all seems fine. Think there also an issue with that split charging relay as mains fridge doesn't work and leisure battery only charges from solar panal. Could this be causing my battery light issues and if so where is it hidden
 
Last edited:
Janet,

be aware that, if you have bridged the relay to provide a permanent 12V supply which looks like a D+, you are likely to experience battery issues, with the vehicle battery, or the habitation battery, or both, since they are likely to get depleted.

That 12V (D+) supply should only be available when the alternator is providing current, to avoid depleting the batteries.
 
HughJampton said:
Janet,

be aware that, if you have bridged the relay to provide a permanent 12V supply which looks like a D+, you are likely to experience battery issues, with the vehicle battery, or the habitation battery, or both, since they are likely to get depleted.

That 12V (D+) supply should only be available when the alternator is providing current, to avoid depleting the batteries.
Click to expand...
only bridged it temporarily to see if it worked, it all be back as was now, but many thanks for the warning.
 
Communicator said:
I think that it is slightly more complicated. Not a smart alternator, but there is an interchange on starting. The BCM needs to see less than 1K ohms when looking into the alternator D+, before supplying initial excitation current. Non OEM alternators may fail to function because of this requirement. There is a thread relating to this, but I cannot locate it at the moment. @koalar has specific knowledge/experience in this area, perhaps he will confirm?
Click to expand...
Here's the thread with the diagnostics for the most common type of alternator

Battery warning light and no power steering | FIAT Bravo 2 (2007+)

Hi all, I have been searching through the forum and read what I could find on the subject - but I just can't find any good leads on how to fix the issue. I recently bought a cheap 2009 Bravo 1.9 Mjet to have as an all round daily driver. It came with battery warning light and no power steering...
www.fiatforum.com

However fiat use at least 3 different types

Bulb controlled
BSI controlled
BSI and ECU controlled
And some also use the B+ for a auxiliary space heater

I can see if I can find the correct information for you
I don't normally follow any thread except for the panda sorry if this information is already in the thread somewhere

But I need

Exact Model
Year
Engine
Is there an auxiliary heater fitted
 
koalar said:
Here's the thread with the diagnostics for the most common type of alternator

Battery warning light and no power steering | FIAT Bravo 2 (2007+)

Hi all, I have been searching through the forum and read what I could find on the subject - but I just can't find any good leads on how to fix the issue. I recently bought a cheap 2009 Bravo 1.9 Mjet to have as an all round daily driver. It came with battery warning light and no power steering...
www.fiatforum.com

However fiat use at least 3 different types

Bulb controlled
BSI controlled
BSI and ECU controlled
And some also use the B+ for a auxiliary space heater

I can see if I can find the correct information for you
I don't normally follow any thread except for the panda sorry if this information is already in the thread somewhere

But I need

Exact Model
Year
Engine
Is there an auxiliary heater fitted
Click to expand...
Hi, Many thanks in advance. Camper is an Adria Mobil - adriatik (according to carte grise). First registered in October 2007. Diesel 2287 cm3. No auxiliary heater fitted.
 
Bad news I don't know what it's based on except it's a 250

The van,minibus, euro 4 there's two version, it's different again if it has start stop or euro 5

Some are ECU or BSI


The good news they are all just two wire

Alternator is A010

Screenshot_20241111-093001.png
Screenshot_20241111-092826.png
Screenshot_20241111-092738.png
Screenshot_20241111-092638.png


Does the battery warning light come on with ignition on

Does the battery warning light stay on while cranking

What is the voltage across the battery terminals before starting, at idle before you rev the engine

These alternators normally self exciting if the revs are raised, if there's no charge if you rev the engine does it then start to charge
 
koalar said:
Bad news I don't know what it's based on except it's a 250

The van,minibus, euro 4 there's two version, it's different again if it has start stop or euro 5

Some are ECU or BSI


The good news they are all just two wire

Alternator is A010

View attachment 455100View attachment 455101View attachment 455102View attachment 455103

Does the battery warning light come on with ignition on

Does the battery warning light stay on while cranking

What is the voltage across the battery terminals before starting, at idle before you rev the engine

These alternators normally self exciting if the revs are raised, if there's no charge if you rev the engine does it then start to charge
Click to expand...
hi, many thanks for wonderfully clear wiring diagram - fantastic.
So the battery light (or bernard as I now like to call him) comes on with ignition and stays on, no flicker ever.
I'll give you D+ voltage at pin 25 of BCM as well as battery
1) ignition on (but not running) BCM D+ 0.67 volts
battery 12.8 volts
2) Ignition on idle (before rev) BCM D+ 14 volts
battery 14.48 volts
3) Ignition with revs BCM D+ 14 volts
battery 14.56 volts

Alternator charging once engine started (no added rev necessary). Battery brand new and stays above 11 volts on crank. Many thanks Janet
 
confuszd said:
hi, many thanks for wonderfully clear wiring diagram - fantastic.
So the battery light (or bernard as I now like to call him) comes on with ignition and stays on, no flicker ever.
I'll give you D+ voltage at pin 25 of BCM as well as battery
1) ignition on (but not running) BCM D+ 0.67 volts
battery 12.8 volts
2) Ignition on idle (before rev) BCM D+ 14 volts
battery 14.48 volts
3) Ignition with revs BCM D+ 14 volts
battery 14.56 volts

Alternator charging once engine started (no added rev necessary). Battery brand new and stays above 11 volts on crank. Many thanks Janet
Click to expand...
So I guess you need to determine why the battery lamps is still on in your second and third results. The BCM is looking suspect?
When that has been determined and rectified then I think the other problems will be resolved.
 
rayc said:
So I guess you need to determine why the battery lamps is still on in your second and third results. The BCM is looking suspect?
When that has been determined and rectified then I think the other problems will be resolved.
Click to expand...
thanks, so as the battery light is only issue I have from BCM, can I just ignore it or would this be folly
 
So far so good

We know the wiring diagram is correct

The voltages at the BSI (BCM) pin 25 is correct

The problem is either the reference ground being used by the BSI is too high or the BSI isn't correct

If you carefully measure pin 25 with the plug disconnected and the ignition on you should get around 8V, please be careful not to short out adjacent pins while measuring
 
Screenshot_20241111-131239.png



With the engine running and some electrics on

Pin 19 and 10 on connector B should be zero volts with reference to the battery negative post


Wires should be
Black
Black and violet
 
rayc said:
Who knows? You could be blissfully driving along and the alternator could have stopped charging and you would grind to a halt.
Click to expand...
10.24 volts at pin 25 with ignition on but not motor engaged - wasn't sure if I has to crank motor before taking reading. So 10.24 be only with key turned to ignition
 
koalar said:
So far so good

We know the wiring diagram is correct

The voltages at the BSI (BCM) pin 25 is correct

The problem is either the reference ground being used by the BSI is too high or the BSI isn't correct

If you carefully measure pin 25 with the plug disconnected and the ignition on you should get around 8V, please be careful not to short out adjacent pins while measuring
Click to expand...
0.24 volts at pin 25 with ignition on but not motor engaged - wasn't sure if I has to crank motor before taking reading. So 10.24 be only with key turned to ignition
 
koalar said:
View attachment 455109


With the engine running and some electrics on

Pin 19 and 10 on connector B should be zero volts with reference to the battery negative post


Wires should be
Black
Black and violet
Click to expand...
wow that was a challenging request, but eventually found them and got a reading off them. Happy to report both pin 10 and 19 were both zero volts with engine running and some electrics on
 
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