flat battery/no battery light

[audi0704]

Hi as in title I suffered a flat battery a couple of days ago,charged it overnight no problems and it wasn't till today I noticed the battery light on the dash is not illuminating at all.Did a multimeter check on battery 11.6v engine off,exactly the same with engine running either on idle or blipping the throttle.
Checked some earlier posts and the Wiki and one suggestion is that the dash bulb can cause the alternator not to charge,also found this in the Wiki but not sure if its confirmed=
( Spoke to a guy yesterday and he said that if I removed the blue wire and earthed it, and the red battery light comes on its an alternator fault, he said that if I earthed the blue wire and didnt get a light it was a bulb/wiring fault...? )
Any ideas/pointers would be appreciated,not a big problem at the moment suns shining,not using wipers,lights etc but all that could change with our weather.
Cheers bob

[Oldiebut goodie]

( Spoke to a guy yesterday and he said that if I removed the blue wire and earthed it, and the red battery light comes on its an alternator fault, he said that if I earthed the blue wire and didnt get a light it was a bulb/wiring fault...? )

Correct.

[colinthefox]

My guess would be that the brushes are worn out on the regulator/brush pack of the alternator.

It's an easy DIY job, and the brush packs are available from most Auto electrical places, or from starter/alternator repair shops. They used to be about a tenner, but last time I bought one I felt ripped off at 30 GBP!

Find the alternator part number and give that to the supplier, to make sure you get the right one. Better still, buy two and keep one as a spare.

[itchyfeet]

didn't I read somewhere some alternators need the bulb to work as this is also part of an excitor circuit?
it's not like that with mine so no personal experience.

[Oldiebut goodie]

Yes.

[audi0704]

Thanks for all the suggestions I will try the blue lead test tomorrow and take it from there,don't want any embarrassing moments at Volkspower this weekend,these vans have a reputation to keep up.Will up-date the post tomorrow with results.
Cheers bob

[audi0704]

Hi just done the blue lead to earth test and the battery light re-appeared so looks like trip to the auto electrician for a regulator and as was suggested will probably buy a spare while i'm there as long as they are not £30,will report back when regulator fitted.
Thanks again every-one who came to the rescue.
Regards bob

[kevtherev]

Tenner from brickwerks

[audi0704]

Thanks kev i'll stick one on my next order (good to have a spare me thinks),just about the same time you posted I was with the local auto electrician guy I've used for decades and he has got me one for tomorrow so fingers crossed,five minute job as a few have said, and i'll be all sorted for Volkspower at Redcar this weekend.
Cheers bob

[audi0704]

UP-DATE Friday picked up regulator from local auto electrician and fitted in 5 mins after spending 20 mins finding something suitable to loosen the screws with alternator in situ, brought back happy memories, just shows how modern cars lull you into an easy life.
Anyway 25 mins later and great news battery light is back on and alternator charging properly once again.
Thanks to every-one for their help and guidance especially the bit about diagnosing the fault using the blue lead and a little word of warning from yesterday,if your alternator is not charging for whatever reason your van will eventually grind to a halt as mine did half a mile from home after a 30 mile journey during which the radio kept going off every time I braked and brake lights obviously drew the current until eventually the gauges on the dash fell to zero and then engine electrics died.
Still I was quite near home and fitted spare battery to get van home.
Thanks again
Bob

[Oldiebut goodie]

Us diesels don't need so much electrickery as you petrol lot - we keep going as long as there is enough to hold the fuel solenoid open.