Ford Ka Battery Warning Light

My wife has a basic Ford Ka 04 reg, low mileage. It drives fine except recently the battery warning light keeps coming on. Any ideas on possible cause? I want to delay the official advice to, "take it to a
Ford dealer immediately" in case there is a relatively simple (and cheaper) alternative. Thanks
Les
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Even a partial diagnosis hinges on WHEN it comes on... engine rpm, battery loading, etc.
--
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
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Backyard Mechanic wrote:

Sorry, but I was labouring under the misapprehension that this was a helpful site. Thanks, but I'd rather buy a new car
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les spewed out this bit, and i'll scatter a few bits myself:

Well then that what you do, go out and buy you a new car. When you probably only need brushes in the alternator, or a battery. The Krusty old Geezers reply was dead on, sir.
--
Mhzjunkie

1 PRINT "Windows XP ERROR"
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les wrote:

The car is a 2004 and you don't have the owner's manual? Anyway, the battery light coming indicates an undercharging condition, usually caused by a dying alternator or/and battery. Invest in a digital Volt-Ohm-Meter and check alternator output at idle, at the battery posts, where it should be a MINIMUM of 13.4 volts while idling, and at least 12.5 volts with everything shut off.
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Sharon K. Cooke wrote:

Thanks to all. Yes I do have a manual - it says take it to your nearest Ford dealer. And apologies to the Krusty Old Geezer. I'd taken the "smartass - DEAL with it" stuff as part of his reply. I'll get my coat.
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les wrote:

Backyard was going to tell you what *part* of the alternator was bad, just the kind of guy he is. BTW, rumor has it, the "krusty & old" part is in his pants. :)
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Front or back? ;)
Ok, I'll go stand in the corner.
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