Focus Zetec battery warning light

[Peterd51]

Hi,

The battery light comes on after ten seconds as I have the alternator 3-pin plug disconnected.

If I pull the fuse (or disconnect the wire) for the 12v 'reference voltage' at the alternator and reconnect the plug...

can anyone confirm that the alternator will stay in 'default' mode and the battery warning light stay off?

Regards
Peter

 
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The battery went flat overnight so I charged it up and went for a drive.

The battery lost a couple of volts during the next night so I charged it up again, went for a drive.

I popped the +ve lead off and inserted an ammeter, 0.5A drain.

Before pulling fuses I disconnected the alternator main lead, drain dropped off, but didn't return when I reconnected the main lead.

After another short drive I reconnected the ammeter, 0.5A drain, I disconnected the alternator 3-pin plug, the drain dropped off, didn't return when I reconnected the plug.

I understand that leaving this plug disconnected puts the alternator into 'default' mode, it charges the battery at 13.9v (confirmed) and wouldn't cause any long-term problems.

I've swapped the battery (Li-On) for a lead-acid 60Ah that I had as a spare.

I've been driving like this for a week, the battery stays fully charged.