Alternator wiring diagram required for Citron Xsara Picasso 2007 1.6 prtrol car.

[ozvtr]

There is nothing special about this alternator. It's only connected to the engine ECU to report an alternator failure to the dash over the CAN BUS.
I have no @#$ing idea what the engineers think an "alternator" or "charging" failure is, because neither seems to bring the battery light on!!!
Anyway, the alternator is self exciting meaning they either work or they don't and they are not reliant on any external electrics.

Tonyfay. What are the symptoms and what diagnostics have you done to establish that it's the alternator?
Have you checked the earths to the gearbox and chassis, the B+ cable to the battery, the battery terminals and the battery itself?
On the surface it seems it's not an alternator problem...or you are very unlucky.

[tonyfay]

Thanks guys for the diagrams , I assume the cable 104 is going to the ECU 12-- unit.

So xantia_6

"if it is a smart alternator, then I would replace the battery without going any further, as a battery with reduced capacity (even though able to start the car after charging) will cause the alternator to under-charge the battery."

Come to think of it , I did change the battery two months ago when my 3.5 year old battery let me down one morning when the charge light came on while driving and at the next traffic lights stop when i turned off the ignition to reset the dash lights , and when i tried to start the car again my starter motor stuck ON and did not release, and burned itself out.
I was then stranded as i could not start the car and had to get a tow home . As this is the car my wife uses i decided to shotgun the faults and I replaced all three, The battery, The starter motor and also the alternator.
My old battery was a 74 AHR capacity and the dealer supplied me with a 60 AHR battery. I did query this with the dealer at the time and he checked his system an said 60 ahr was fine .

It was then that the intermittent battery charging symptoms started to show up. for instance ,
I would start the car and drive about 200 meters and the charge light would come on , and i would continue to drive for about 5 minutes and the light would go out again and stay out . The next time I start the car the same symptoms would happen again , or some times it might not happen until two days later after having completed three or four journeys during the two days .

When the battery let me down this most recent time, i manually charged the battery to full capacity , The charge light does not come on now during all these tests even though the alternator output sits at the battery voltage level and does not rise while the engine is running.

Tomorrow I will test the alternator for smart type by unplugging the small signal cable and see if the voltage rises on the alternator output cable.

if the voltage rises will purchase a replacement battery with a higher capacity .

I report back here then . cheers for now

[tonyfay]

ozvtr

I will recheck the earths to the gearbox etc,
thanks for your input on the operation of the alternator.
regards Tony

[xantia_v6]

There is nothing special about this alternator. It's only connected to the engine ECU to report an alternator failure to the dash over the CAN BUS.
I have no @#$ing idea what the engineers think an "alternator" or "charging" failure is, because neither seems to bring the battery light on!!!
Anyway, the alternator is self exciting meaning they either work or they don't and they are not reliant on any external electrics.

That is not correct. The alternator output voltage is controlled by the engine ECU and BSI, which use an algorithm that attempts to keep the battery charged while using the minimum amount of fuel.

The algorithm seems to allow the battery to run down to less than half charge before it recharged. The problem is that it estimates the current level of battery charge by taking the nominal capacity of a new battery and subtracting the energy used by the electrical system since the time when it thinks that the battery was last fully charged.

The result is that an old or lower capacity battery is at significant risk of going flat before the ECUs decide that it needs charging.

[tonyfay]

V xantia_v6
are you saying i need to buy a higher capacity battery, what capacity should buy?

[xantia_v6]

The battery should be the original specification or a little more in AH. On some models it may be possible to select a different battery capacity in The BSI configuration.

[shtu]

Tomorrow I will test the alternator for smart type by unplugging the small signal cable and see if the voltage rises on the alternator output cable.

In my experience, disconnecting the small 1-wire connector will switch the alternator to full output all the time.

(this is on a 1.6 hdi berlingo, so ymmv)

It's rare but not impossible that the new alternator is faulty, but don't jump to conclusions re new batteries etc. The battery in my van was -goosed- and the alternator would still output loads of voltage.

[ozvtr]

That is not correct. The alternator output voltage is controlled by the engine ECU and BSI, which use an algorithm that attempts to keep the battery charged while using the minimum amount of fuel.

The algorithm seems to allow the battery to run down to less than half charge before it recharged. The problem is that it estimates the current level of battery charge by taking the nominal capacity of a new battery and subtracting the energy used by the electrical system since the time when it thinks that the battery was last fully charged.

The result is that an old or lower capacity battery is at significant risk of going flat before the ECUs decide that it needs charging.

Not on this particular setup. There are far more advanced arrangements in other vehicles with power management systems, true, but those alternators have more control wires than just the one wire.
For a 2007 vehicle, I'm assuming this is a TU5JP4 engine with a BOSCH ME7.4.4 ECU. A 1.6 prtrol (sic) from the title. The 7.4.4 does not have a fancy alternator control facility. It just runs a plain vanilla alternator with an internal regulator.
Of course if it's a different engine and those circuit diagrams are incorrect...well, then I have nothing to go on and the OP needs to clarify things!

[xantia_v6]

I did check the wiring diagrams and it has a smart alternator connected directly to the engine ECU via a one wire LIN bus.

[tonyfay]

Hi All,
Sorry for the long delay in getting back to you. Just giving you all an update on my alternator Issues.

The new alternator that I fitted turned out to be faulty. it would not give a charging output voltage at Idling or below 1500 revs, and even then that was a bit flakey.

I returned that alternator to the supplier who replaced it with another aftermarket unit.
When I fitted this I was presented with 14 Volts output from the moment the engine started at Idle.

I also installed 62Ahr Battery to replace the 60 Ahr battery.
I have been monitoring the output to the battery using a cheep chinese usb phone charger with digital voltage readout that plugs into the cigarette lighter socket
It helped me diagnose the flakey issues on the faulty alternator.

https://www.aliexpress.com/ssr/30000051 ... 306c4b6b8b

No issues since , Case closed.
Thanks to all who chipped in with help, suggestions and diagrams.

Problem Fixed.
Kind regards,
Tony