Battery warning Light

TheBody

Hi all.

The battery warning light came on on my 1.4 petrol ford focus (2007) this morning. So I checked, the alternator, the battery, all the fuses and all are ok. Now here is the thing, after I checked all these things, I noticed that the front windsrceen heater has stopped working. As in, when I push the button in, the light in the switch doesn't come on and it doesn't heat up. It seems to be a bit of a coincidence that this would stop working at the same time as this warning light starts. Any ideas on what the problem is or are these events related?

dieselbug

This is a smart charging system.

Ecu will disable non essential battery loads if the battery condition is below given parameters. The light is controlled by the ecu and not directly by the alternator.

alternator.http://www.valeoservice.com/data/master/webfile/2945759434DDE6E8714173.pdf

TheBody

dieselbug wrote: »

This is a smart charging system.

Ecu will disable non essential battery loads if the battery condition is below given parameters. The light is controlled by the ecu and not directly by the alternator.

alternator.http://www.valeoservice.com/data/master/webfile/2945759434DDE6E8714173.pdf

Thanks for that. Me thinks I'm getting out of my depth!! Off to the garage in the new year for me.

shamwari

Certainly on the diesel focus, the clutch pulley on the alternator gives a fair amount of problems that can lead to the alternator being condemned when it isn't at fault.

Also as dieselbug has said, this is a smart charging system. It requires a calcium battery instead of a bog standard lead acid one. And as the smart charge system is controlled by the PCM, the PCM can also yield up diagnostic fault codes IF it is scanned with a suitable scantool. A generic OBD scantool usually wont suffice...

Also, the front screen heater is instantly disabled in a low volts situation on these

shamwari

One other thing that is important to note here and isn't covered in the Valeo PDF above. The output from the smart alternator is varied to meet demand / load by the PCM. In certain circumstances, it can command an output of around 17.5 volts, usually where the load is high and external temperatures are cold. Therefore, a car with a smart charge system should never be jump started, otherwise the car providing the power can be zapped if the PCM in the Ford decides pump out 17.5V when it starts ! :eek:

TheBody

shamwari wrote: »

Certainly on the diesel focus, the clutch pulley on the alternator gives a fair amount of problems that can lead to the alternator being condemned when it isn't at fault.

Also as dieselbug has said, this is a smart charging system. It requires a calcium battery instead of a bog standard lead acid one. And as the smart charge system is controlled by the PCM, the PCM can also yield up diagnostic fault codes IF it is scanned with a suitable scantool. A generic OBD scantool usually wont suffice...

Also, the front screen heater is instantly disabled in a low volts situation on these

I was thinking about this too. We scanned the car with a cheap scanner and it didn't display any faults. Thanks for your input.

shamwari

TheBody wrote: »

I was thinking about this too. We scanned the car with a cheap scanner and it didn't display any faults. Thanks for your input.

Yeah, any manufacturer specific codes on those between P1000 and P1999 won't be displayed on a generic reader unless
(a) the detected fault also generates a generic code between P0001 - P0999, and
(b) that the aforementioned code created in (a) also puts the engine management light on.
Usually these would be faults that would create emissions issues.

I thinks that P1000-P1999 are not EOBD codes and therefore are stored in a different area of the PCM's memory which a high end / Ford specific scantool can only read. If you could read it, you'd get something like a P1632 or similar which relates to smart alternator faults. I can check my notes later if you need this info.

shamwari

Here's another thing you could do.

Get a voltmeter and measure and note the battery volts with the engine off

Then start the engine and measure the voltage again. If the battery light is on but the battery volts read higher when it is running, chances are that your alternator might be ok, but it might be the connections for the PCM smart monitoring referred to in the Valeo PDF.

If volts are lower, leave the engine running and see if the battery light goes out. If it does, read the battery volts again and if they are up, check wiring and connections, and the clutch pulley before condemning the alternator.

TheBody

shamwari wrote: »

Here's another thing you could do.

Get a voltmeter and measure and note the battery volts with the engine off

Then start the engine and measure the voltage again. If the battery light is on but the battery volts read higher when it is running, chances are that your alternator might be ok, but it might be the connections for the PCM smart monitoring referred to in the Valeo PDF.

If volts are lower, leave the engine running and see if the battery light goes out. If it does, read the battery volts again and if they are up, check wiring and connections, and the clutch pulley before condemning the alternator.

I did this and the voltage increased. Also, you can hear the pull on the engine change when you turn on all the electrical stuff. That's what makes me think the altenator is ok. The battery is brand new. I'll just bring it to the mechanic in the new year and let him plug it in to see what he can find.

So do you think the front windscreen heater might be ok and the car is only preserving the energy?

shamwari

TheBody wrote: »

I did this and the voltage increased. Also, you can hear the pull on the engine change when you turn on all the electrical stuff. That's what makes me think the altenator is ok. The battery is brand new. I'll just bring it to the mechanic in the new year and let him plug it in to see what he can find.

So do you think the front windscreen heater might be ok and the car is only preserving the energy?

The front windscreen heater will become unavailable if there is a charging fault or low volts detected. So when the charging fault is fixed, the windscreen should be operative again.

The red light actually serves two purposes in your case: it indicates a charging fault, and also any fault conditions detected with the smart charge system.

I take it that the light is staying on and not going out? Are the battery terminals have tight and clean connections? You say that the battery is brand new: is it a calcium battery? These are necessary on a Smart system.

TheBody

shamwari wrote: »

The front windscreen heater will become unavailable if there is a charging fault or low volts detected. So when the charging fault is fixed, the windscreen should be operative again.

The red light actually serves two purposes in your case: it indicates a charging fault, and also any fault conditions detected with the smart charge system.

I take it that the light is staying on and not going out? Are the battery terminals have tight and clean connections? You say that the battery is brand new: is it a calcium battery? These are necessary on a Smart system.

Yes, the light is staying on. The battery is a Bosch Silver one like this:

shamwari

TheBody wrote: »

Yes, the light is staying on. The battery is a Bosch Silver one like this:

I've sent you a PM, have a good read of it.;)