Problem. battery light has started to come on and then go off almost randomly though not when the engine is under load ie motorway etc.

Seems to come on more when braking or changing gear.

ABS and ASR lights came on whilst on the drive but went again after a brief blip of the throttle.

Strange sound appears to be coming from the alternator which also disappeared after some throttle.

Car; Fabia 1.9TDi PD 100 Engine code ATD

New battery time or load sensor wire maybe. Ambient temp was 4⁰ and overnight was -2⁰

Recent changes; oil/ oil filter and fuel filter yesterday. Fuel filter changed according to Haynes guide and no leaks.

 

I have VCDS lite and a third party cable but no fault codes found (I think)

 

The note changes after a blip on the throttle but not easy to pick up.

 

https://www.youtube.com/watch?v=jQaks0TbfCE&feature=em-upload_owner

 

 

I'd check the DFM wire just as a matter of course. Also check charge rate at idle and under electrical load. I'd also check voltage drop along your battery earth lead.

But sounds like maybe the alternator is due for a change.

I'd check the DFM wire just as a matter of course. Also check charge rate at idle and under electrical load. I'd also check voltage drop along your battery earth lead.

But sounds like maybe the alternator is due for a change.

 

Thanks for the fast response, mate. But, DFM?

No means to check the charge rate here unless I can do that in VCDS lite.

Alternator's getting on a bit, was hoping it wasn't going to be that though lol

 

Many thanks again, Ross.

Sounds like a check of voltage regulator brush length is in order.

 

I say sounds like, but I mean 'reads like' 'cos I can't make the vid work.

Dfm wire, mine comes on when braking occasionally and my dfm wire is broken

Do you not have a multimeter? if not buy one they are less than a fiver

DFM wire AKA alternator load sense wire.

 

I'll have a look.

 

http://www.briskoda.net/forums/topic/247393-dfm-wiring-aka-alternator-sense-wire-asr-faults-no-battery-light-alternator-not-charging-etc/

Sounds like a check of voltage regulator brush length is in order.

 

I say sounds like, but I mean 'reads like' 'cos I can't make the vid work.

+1   and dirty sticky brush holders

Update, left car on the drive as it was ****ing it down. Got in to drive home 12 ish miles including motorway, no battery light and all seemed normal. Weird.

Update, left car on the drive as it was ****ing it down. Got in to drive home 12 ish miles including motorway, no battery light and all seemed normal. Weird.

Mine only comes on intermittently, when it comes on at idle it wont gp away until I drive off amd stop again, if it comes on at all

Could also be the alternator clutch sticking "open".

 

The ABS and ESR are the first systems shut down to save electricity when the battery charge starts falling.

If the alternator is making a noise it's probably not long for this world

another update. Still no battery light;

 

Popped into works Mech Aids dept this morning as I had some equipment due for testing. Turns out the tester is a forum member

 

Anyway, he lent me a multimeter so I tested the battery voltage. 12.9V, ignition on then started, dropped to 9.8V then went up to 14.6V so that seems fine.

 

Just keep an eye on things and check the load sensor wire hadn't just come loose I guess.

If the alternator is making a noise it's probably not long for this world

no more noises from the alternator either. Might replace it as a matter of course anyway as pay day's due.

Did you drive through a lot of wate? that can do it 

12.9v static is too high as a matter of accumulator physics and chemistry: just under 12v (2 per cell) is more like it for lead-acid.

 

The 9.8v under deep drain (starter turning) seems about right though.

 

So even taking v1 off the 14.6v running still returns a positive charge engine running. It's rare, but I suppose it could actually be that the idiot light has failed.

Where did you get that info from?

Could also be the alternator clutch sticking "open".

The ABS and ESR are the first systems shut down to save electricity when the battery charge starts falling.

Did you drive through a lot of wate? that can do it 

Not recently. All was dry underneath the previous day when I changed the oil etc.

12.9v static is too high as a matter of accumulator physics and chemistry: just under 12v (2 per cell) is more like it for lead-acid.

 

The 9.8v under deep drain (starter turning) seems about right though.

 

So even taking v1 off the 14.6v running still returns a positive charge engine running. It's rare, but I suppose it could actually be that the idiot light has failed.

Pretty sure those were the figure but I'm going to get a multimeter this weekend and recheck.

By 'idiot light' I take it you mean the battery warning light? That still comes on with the ignition and is going off as it should.

Where did you get that info from?

The systems that shut down first bit? That's from practical experience.

another update. Still no battery light;

 

What di you mean by this then>

Pretty sure those were the figure but I'm going to get a multimeter this weekend and recheck.

By 'idiot light' I take it you mean the battery warning light? That still comes on with the ignition and is going off as it should.

"Idiot light" is a generic for all dashboard warning lights, but in this case referencing the alternator light yes.

The systems that shut down first bit? That's from practical experience.

It's absolutely true!

I've been pulling my hair out as to why them lights keep coming on for the last few months.

Replaced my battery yesterday as it wasn't starting after few days of jump starts.

Now them lights have dissappeard ...Hopfully for good.[emoji2]

That piece of info will help a lot of people on here with the issue of them lights coming on at start up.

Cheers for that[emoji106]