Peugeot 607 charging issue

[Quercus81]

Hello,

And greetings from Finland! This will be my first post, and unfortunately a long one. I'll try to include as much information as possible, in case anyone would be able to help me in this matter. I'm getting quite desperate...

I recently bought facelift Peugeot 607 2006 2.2 petrol (produced in july 2005, older model) and it's previous owner had been using it without problems until some very rainy weather, when the car suddenly informed that charging/battery system fault. He changed the alternator to a new one produced in china, but it didn't start charging. That's when he quit and sold it to me for cheap.
I just in case tried to replace the alternator with the same model but new unit to rule out a faulty one, but that didn't solve the problem. The original alternator I had given away after checking that it was worn beyond easy repair.

I did some measuring and discovered that the alternator exciter voltage was pretty much zero. Or to be exact, voltage meter read 0 for five seconds and then for half a second rising to 8-10 and falling back to 0 for 5 seconds. In comparison, my 406 exciter voltage does the same 0-8v but sweeping between it so that there is voltage all the time.
I have checked many ground points, fuses, and also checked that those two thin wire that connect to the alternator connector should be fine. I checked from Sedre that the other wire goes to ECU, and has stable voltage. The exciter wire goes to engine fuse box (BSM). I tried to follow if there could be any other components involved in giving the exciter voltage, but couldn't find any.

If I give the initial exciter voltage from 12v line to the alternator, it starts charging and works until I turn engine off! But no revving or anything else starts it, not a single time. SO I was thinking that the alternator is not faulty, but could it be wrong type? Some alternators excite themselves (there is probably a better term for that though...), but could the electronics of this charger be incompatible or different to the previous Valeo Class 15 charger?

After countless of hours of scratching my head I ended up ordering used BSM unit from Poland, since the brand new ones were 400€. But to my disappointment it wasn't any better. Just now I cannot be 100% sure that both of the BSM-units don't have the same fault...It is unlikely, but still a possibility.

Then I entered the world of diagnostic tools and ordered a full chip Lexia/pp2000 tool. I plugged it in and was able to go through the menus and tests for a while, but didn't learn as much as I wanted. What was bit weird was that motorized boot ecu was showing "connecting error", even though the boot opens and closes. Also tire deflation monitoring system was giving a "Fault in the vehicle speed information received by the CAN from ABS or ESP ECU". Everything else is working well.

The VIN/VIC code of the car is VF3**************[VIN obfuscated, can be read by forum staff]. Somewhere in the pp2000 it said this is L5 variant, whatever it means. I'll be happy to share more information if it helps.

One more thing. The previous owner had replaced recently the blower resistor in the passenger feet space. I investigated it closer and noticed that the negative and positive cable connector had melted and short circuited. Now it has new unit and is working well, so I don't think it had fried anything, but just good to mention everything.

I'd be very grateful for any help and ideas that could help me to solve this problem

Now I don't know where to go from here, so any ideas are welcome.

[mickthemaverick]

You mention many things done there, but you did not say if the battery is in good condition showing 12.7V when all turned off?

[xantia_v6]

Is this a LIN bus alternator? If so it is normal to measure 0V on the digital control wire. Does the alternator charge if the control wire is disconnected?

[Quercus81]

Is this a LIN bus alternator? If so it is normal to measure 0V on the digital control wire. Does the alternator charge if the control wire is disconnected?

Is the control wire the other one in the connector, the other one being exciter wire? In that case I haven't tried unplugging that wire separately, but it doesn't start charging regardless of the connector as whole being plugged in or not. When it gets exciter voltage, it charges and doesn't stop charging if I unplug the connector.

You mention many things done there, but you did not say if the battery is in good condition showing 12.7V when all turned off?

Ah I have probably forgotten some other details too. I have charged it full couple of times and it shows like 12.8v of I remember correctly. I tested it also with my other car's battery, and that one is less than two years old.

These are the only identification I found of the alternator. It cost over 200€ so it shouldn't be rubbish, but you can never be sure...Sorry for the big pictures, I don't know how to make them smaller.

[xantia_v6]

Here is the circuit diagram for a 2005 605 2.2 including the alternator (component 1020):

Note that (assuming that this is the correct version), there should be only one wire (1087) connected to the 2 pin connector. I am still not sure if it is a digital control (LIN bus) or analog control alternator.

[Quercus81]

I think I have mistaken with the L5-variant, because for that variant Sedre indeed shows only one wire to the alternator connector, and without that variation it shows as it is with my car, one going to ECU and other one to BSM. Just that Diagbox was showing somewhere that it is L5, I have to check that again.
But I don't think it is an LIN-alternator, because this one has DFM (ECU), L (Exciter) and + cables only.

Here is what I believe should be correct diagram if it is not L5 variant.

[xantia_v6]

Thinking about this a bit more, if your car has 2 wires going to the exciter plug on the alternator, then it should have an alternator with DFM.
I do think that it is worth checking that the replacement alternator(s) are in fact DFM, not LIN, as the LIN alternators have a similar 2 pin connector (with one pin unused).
You could try a couple of tests which should identify which type of alternator is currently fitted. A LIN alternator will produce a constant 14.4V if the exciter plug is disconnected. A DFM alternator should produce about 14.4 volts with the exciter pin connected to the battery and the DFM pin disconnected.

[Quercus81]

At least the replacement alternator product info says it has DFM and L, so it should be non-LIN. I'll anyway check whenever I get chance to do it in bit warmer temperature than -15 celsius.

[Quercus81]

Thinking about this a bit more, if your car has 2 wires going to the exciter plug on the alternator, then it should have an alternator with DFM.
I do think that it is worth checking that the replacement alternator(s) are in fact DFM, not LIN, as the LIN alternators have a similar 2 pin connector (with one pin unused).
You could try a couple of tests which should identify which type of alternator is currently fitted. A LIN alternator will produce a constant 14.4V if the exciter plug is disconnected. A DFM alternator should produce about 14.4 volts with the exciter pin connected to the battery and the DFM pin disconnected.

I tested that the alternator is producing 14.2-14.4 when I take exciter wire from the battery. No difference whether DFM pin connected or disconnected. But this I pretty much knew.

Also ruled out bad exciter cable between BSM connector and alternator. It is still a mystery why there is no proper exciter voltage.

Would it work if I took the excitement voltage from the starter? From the wire that tells the starter to work when starting the car. It would be a workaround that would make it more convenient to use the car until I some day manage to solve the original problem. That wire should only get the voltage for a second or so, just enough to get the alternator to start charging, not supply a continuous voltage there.

[Mihael_M]

On the Autodoc website, alternators with DMF control are offered for this type of car.
https://www.autodoc.co.uk/car-parts/alt ... omSearch=1
To check functionality, you should attach an oscilloscope to the L contact that comes to the alternator. The voltage of the alternator on the + B contact must always be there while the engine is running , but it changes (on my Megane it was 14.5 V after starting and later it drops to 13.5 V).
I would not advise you to connect the signal from the starter. It is not clear to me which scheme you have on your car. The one with only one 1087 wire or this scheme with two wires 1087 and 104.
If only one wire is 1087, then you should check if it has good contact with BSI.

[xantia_v6]

The exciter voltage should come from a circuit that has 12V when the ignition is switched on. I am not sure which is the most convenient wire for that, but there must be something around the engine fuse box.

[Quercus81]

On the Autodoc website, alternators with DMF control are offered for this type of car.
https://www.autodoc.co.uk/car-parts/alt ... omSearch=1
To check functionality, you should attach an oscilloscope to the L contact that comes to the alternator. The voltage of the alternator on the + B contact must always be there while the engine is running , but it changes (on my Megane it was 14.5 V after starting and later it drops to 13.5 V).
I would not advise you to connect the signal from the starter. It is not clear to me which scheme you have on your car. The one with only one 1087 wire or this scheme with two wires 1087 and 104.
If only one wire is 1087, then you should check if it has good contact with BSI.

I have the newer model of the car that has two wires to the alternator connector, 1087 (coming from engine fusebox) and 104 (ecu).

Unfortunately I don't have an oscilloscope, but I can try to find one to borrow.

The exciter voltage should come from a circuit that has 12V when the ignition is switched on. I am not sure which is the most convenient wire for that, but there must be something around the engine fuse box.

And it should probably not be constantly on, so that's why I thought of the starter wire.

If someone has 607 from 2005 on (or 407 might work too) with the two wire connector to the alternator, could you please measure the voltage coming to the alternator connector L wire (it's the yellow one towards the back of the car) when the connector is DISCONNECTED and the car is started? (but not charging because that plug is not connected.)

It might get voltage before the car is even started, just the ignition turned on. That would help me to know if the exciter voltage should behave like that when ecu/bsi is not getting feedback from the alternator, or if it should have voltage even when the alternator is not running.

In case other car behaves the same way, the problem may be with incompatible alternator. It's an unlikely possibility, but I have to rule it out.