Battery Light Flickers Whilst Driving - HELP

[vinney515]

Hi,

I need some help with my car. I've an Audi A4 19tdi Sport and recently whilst driving the the battery lights flickers on and off.

I first noticed it, when I attempted to shift down gears to over take a slow vehicle when the radio cut out when the revs were above 3000. There was no loss of power to vehicle (apart from the radio cutting out).

After this the car was not driven for two days and when started up again the light was again flickering. The vehicle started fine, not issues with the pump or steering and fan belt looks intact and battery looks ok. However, wilst driving the light was flickering contantsly. After an hour of driving with no electrics on the light was not flicker but when revved agressively it would again light up and cut off again.

Does anybody have an idea what might be causing the issue? Is it a weak battery or a alternator that looks like it maybe on its way out? or could this be something else?

Would appreciate any help...

Thanks

VJ

[Crasher]

That sounds like the alternator is failing but it isn't a common problem. Does the drive belt jump around, especially as the steering is turned?

[vinney515]

That sounds like the alternator is failing but it isn't a common problem. Does the drive belt jump around, especially as the steering is turned?

Thanks for that, i'll try and have alook later on... If that fails and seems to be in working order, do you recommend getting the car put on the diagnostics? Any ideas how much it would cost to get fixed?

[Crasher]

A fault code scan probably won't tell you any more information other than you have a voltage supply issue and from the engine ECU you could expect to see something like;

16946 - System Voltage: Too Low P0562 - 35-10 - - - Intermittent

or

18010 - Power Supply Terminal 30: Voltage too Low P1602 - 35-10 - - - Intermittent

A fault code read at an independent specialist or garage should cost you around £25 to £30. More informative would be a current delivery and voltage output test on the alternator using a multimeter and this could be done in around half an hour.