Red battery warning light illuminating

[rhencullen1989]

Hi all, as the title says, my wife was driving my 1.8T quattro s-line today and the battery warning light illuminated, when she slowed down, it went out, and when she speeded up it came back on!

When i came back from work tonight i put a multi meter across the battery terminals with the engine off and got 12.5 volts, started the engine and got 14 volts, went for a 10 mile drive and no lights came on, back home and still pulling 13.8 volts.

Is this just a little electrical gremlin or the start of a failing alternator. The battery was new about 6 months ago. mileage is 78K, so not very high.

[Guest 2]

My old MK2 Mondeo use to do this but when you pressed the clutch the light came on and when the clutch was depressed it went off.

It turned out to be the alternator and the battery was proved tired too.

Hope that helped a little but I'm sure someone with more oil and spanners in their blood will tag along soon :)

[Alan02]

Its hard to say without further testing. Have you checked Battery Leads, Alternator wiring? Always a good place to start. Run engine and with all consumers turned on, you should still get a healthy voltage across the battery, as a simple test.
Possibly worn Brushes on the Voltage Regulator can also give similar symptooms.