Technical 2007 Panda 1.3 multijet charging issues

[nige g]

Hi all
I'm struggling to fix a charging problem with my 07 1.3 multijet

Had the occasional dash battery light flashing whilst driving for a few weeks, this eventually stayed lit and battery obviously discharged over time.
It's done 140k miles I thought the alternator has expired, so fitted a new one but it hasn't made any difference.

All fuses are good
The earth strap from gearbox to chassis is good, (but I ran an extra cable from battery neg to engine block, but no effect)
I removed the small wire from the alternator and with ignition on I'm getting 12v, so that looks good.

Here's the rub, if I turn the ignition on & wait for the glow plug coil to go out on the dash & then start the engine the battery light stays on & there's no charge from the alt.
If I turn the ignition on & start the engine straight away, the battery light goes out & I'm getting 14v!
I drove for 10mls with no issue, but can't trust it too far from home.


I'm at a loss as to what to look at next, anyone got any pointers?
Grateful for any help
Nige

 

[Mike1alike]

What brand is the new alternator?
There are a couple of threads here (other sections too, not just Panda) with new alternators that do that, have the light on dash on.
Did you clean the (+) cables' contacts on the alternator?

 

[The Panda Nut]

I have no idea if this will help, but years ago I had this with a Citroen. Iwas literally about to rip the wiring harness off the car when the mechanic at my garage scratched his head and said wiat.

It was caused by a faulty fuse in the charging circuit. The fuse wire had broken at one end. The fuse looked in tact. It had been flashing for week or two. A new fuse solved it, so, check fuses and then check continuity of the wires from the alternator to the car / battery. A bad connection or broken wire sounds likely but I would need to be there to look to say where to start on this. A 9v battery and a bulb will be useful to do continuity checks. I hope you find the fault which is probably silly.

 

[nige g]

What brand is the new alternator?
There are a couple of threads here (other sections too, not just Panda) with new alternators that do that, have the light on dash on.
Did you clean the (+) cables' contacts on the alternator?

It says NAPA on the box, I expect it's from china.
I must admit I didn't clean the cable contacts, they didn't look corroded but I could give them a spruce up, won't do any harm. I'm not convinced that the old (or new) alts are faulty, I think the it's elsewhere. Could it be the ignition switch contacts, or the engine ECU?

 

[nige g]

I have no idea if this will help, but years ago I had this with a Citroen. Iwas literally about to rip the wiring harness off the car when the mechanic at my garage scratched his head and said wiat.

It was caused by a faulty fuse in the charging circuit. The fuse wire had broken at one end. The fuse looked in tact. It had been flashing for week or two. A new fuse solved it, so, check fuses and then check continuity of the wires from the alternator to the car / battery. A bad connection or broken wire sounds likely but I would need to be there to look to say where to start on this. A 9v battery and a bulb will be useful to do continuity checks. I hope you find the fault which is probably silly.

Hi, thanks, I've had all the fuses out and checked each one for continuity, I might change the 4 that relate to starting & charging see if that changes anything. Wiring continuity is next. It's all a bit tight for space back there!. Need a dry and warmer day as well.

 

[The Panda Nut]

Hi, thanks, I've had all the fuses out and checked each one for continuity, I might change the 4 that relate to starting & charging see if that changes anything. Wiring continuity is next. It's all a bit tight for space back there!. Need a dry and warmer day as well.

Well good luck these things are really annoying.

 

[Mike1alike]

Could it be the ignition switch contacts, or the engine ECU?

No, I don't think that is. The alternator is old type, "fixed alternator", right? It's not smart, with controled charging, is it?
It's something with the voltage regulator. That's why when you put the ignition on and you wait, it doesn't change. Sometimes goes wrong there, in the regulator and it cuts the output voltage off.
As I said, I do remember reading in here about this kind of problem. I'll take a look, see if I can find something to help you.

 

[nige g]

No, I don't think that is. The alternator is old type, "fixed alternator", right? It's not smart, with controled charging, is it?
It's something with the voltage regulator. That's why when you put the ignition on and you wait, it doesn't change. Sometimes goes wrong there, in the regulator and it cuts the output voltage off.
As I said, I di remember reading in here about this kind of problem. I'll take a look, see if I can find something to help you.

That's really good thanks for your help

 

[Mike1alike]

@nige g, take a look on this thread:

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

In a way it's good news as I rather swap alternator than BCM. But it's still very puzzling.... Why wouldn't an non-OEM alternator work ? Every part shop being it online or indepentent garage offers Hella or Bosch for our cars. One should think there are numerous stories about the same problem...

www.fiatforum.com

 

[Mike1alike]

And this one:

Alternator charging light | FIAT Stilo

I believe I have deleted all my Stilo pictures now but if you do a search you may find a post i did on the D4, way back in history which probably had a few pics Rather than split the connector just back probe the connector on either side and check for continuity ( a lot less drastic:)) The...

www.fiatforum.com

 

[koalar]

Start at the beginning

Voltage on small wire ignition on
Voltage on small wire cranking
Voltage on small wire engine running

Koalar random thoughts | FIAT Panda (Mk3)

You can tell if the coil pack is getting a control signal and giving a good spark like this If one is weeker and the spark does not jump as far than the others it's suspect It is possible to get a jolt if you do something wrong, probably not a good idea if you have a pace maker As long as the...

www.fiatforum.com

If you raise the revs to 4K does the alternator start charging


When it's charging is it exactly 14V or 14.2V
If you put the main beam, rear heated window and blowers on full what does it drop to
If you raise the revs does it rise back up again

 

[nige g]

And this one:

Alternator charging light | FIAT Stilo

I believe I have deleted all my Stilo pictures now but if you do a search you may find a post i did on the D4, way back in history which probably had a few pics Rather than split the connector just back probe the connector on either side and check for continuity ( a lot less drastic:)) The...

www.fiatforum.com

Crikey this is all very complicated but I'm more aware now that it might not be just a simple wire/earth issue
Thanks again

 

[nige g]

Start at the beginning

Voltage on small wire ignition on
Voltage on small wire cranking
Voltage on small wire engine running

Koalar random thoughts | FIAT Panda (Mk3)

You can tell if the coil pack is getting a control signal and giving a good spark like this If one is weeker and the spark does not jump as far than the others it's suspect It is possible to get a jolt if you do something wrong, probably not a good idea if you have a pace maker As long as the...

www.fiatforum.com

If you raise the revs to 4K does the alternator start charging


When it's charging is it exactly 14V or 14.2V
If you put the main beam, rear heated window and blowers on full what does it drop to
If you raise the revs does it rise back up again

Hi
Thanks, I'll check all these and report back (be early next week as I'm helping son move house)
With small wire disconnected ignition on I get 12v
I think small wire connected ignition on it was something like 1.2v
Thanks again

 

[koalar]

Hi
Thanks, I'll check all these and report back (be early next week as I'm helping son move house)
With small wire disconnected ignition on I get 12v
I think small wire connected ignition on it was something like 1.2v
Thanks again

Never seen 12V

It usually 7.5-10.5V

Not overly worry it higher than normal

At least it proves it's not shorted it earth and there no brake in the cable

 

[koalar]

Crikey this is all very complicated but I'm more aware now that it might not be just a simple wire/earth issue
Thanks again

The light on the dash is computer controlled

It test the little wire at ignition on, if it detects a problem the light stays on

It then senses the voltage once the revs are over 700 rpm if it's above 5.5V the light goes out

It should only then put the light back until it senses below 4.5V

Measure the resistance from the small wire to the alternator case.it should be around 1.5K from.your symptoms I suspect yours will be a order of magnitude higher

It's a stupid system, as often the first time you know the battery isn't charging is when you turn something electrical on or hit the brake and the engine stops