Battery warning light issue.

[bluphoto]

My transit (56 plate 2.2 110/280) has, for the last 2 or 3 mornings, had the battery light coming on on startup. The thing is, if I switch the engine off and then on again, it goes away. If I don't switch the engine off, then it doesn't go away for the whole journey (could be an hour or more). Then, as soon as I switch off and on, the light goes out.

Does the computer "remember" a momentary charging problem and leave the battery light on, even the charging issue goes away, until I reset it by switching the engine off and on again? Alternatively, is the battery light DIRECTLY connected to the charging circuit, or is that circuit monitored by the computer, which in-turn controls the battery light separately?

How can I tell if the battery really is charging, whether the light is on or off?

Is there any other problem that might cause the battery light to come on, other than a charging problem?

At no time is there an engine management light on, so would there be any fault logged in the computer?

What's the best way to diagnose this?

cheers

[ake]

Its caused by moisture or corrosion inside the alternator which builds up over night, thats why it works fine the second time, alternator will die eventually but should last a while yet. I'm not 100% sure but I think charging is controlled by BCM