Battery drains overnight

[Jonse123]

My 1998 A4 1.9Tdi has been fairly trouble free during the past 5 years I've owned it but I have a head scratching problem that I'm hoping someone could give some help with.

Over the Xmas period I hardly drove the car & , like many others , found a flat battery in the New Year.
I immediately thought it was the battery & after charging fully I refitted the battery & car started 1st. time.
Next morning battery was completely flat again.
I assumed it must be a duff battery ( although a Varta less than 4 years old ) & duly paid £90 for a BOSCH battery.
Again started 1st time , started next morning , completly dead by the end of the day.
Car easily starts & runs as normal when started with a fully charged battery.

Saw a couple of threads in this forum & followed members advice to remove battery cable & connect volt meter between cable & battery post. I can see 12V on the meter & proceeded to remove fuses to see where a short might be.
Removed ALL fuses from fuse box & can STILL see 12V on voltmeter.!
Am I doing this correctly?
If yes shall I continue this check but start unplugging relays ?

I can not find any reference in owners manual or Haynes manual as to fuses for the radio or the CD changer ( I fitted CD changer in boot to existing lead couple of years ago without any problems )
Is there a fuse for the radio / changer ?

I can not hear any motors / pumps running with ignition off only thing I have noticed that coincides with this problem is that the one touch electric window power down or power up is now not working . ( JUST READ IN OWNERS MANUAL THAT THIS IS CAUSED BY THE BATTERY BEING DISCONNECTED )

Managed to get to work today by removing / reattaching negative lead from battery ( again starting 1st. time so far )
Any advice would be greatly appreciated thanks.

[Jonse123]

I have found water under the pollen filter & in the blower asembly & a damp area in the passenger footwell.
Even with all fuses removed & radio removed I still measure more than 250 mA drain on the battery.
Have fixed leak & left carpe folded back to hopefully dry out.
Does anybody know ( or know where to find ) what the current ( amp ) draw should be for this car with ignition off? Thanks.

[hagis]

The water will probably be caused by the drain under the battery being blocked.

https://www.vwaudiforum.co.uk/forum/s...ghlight=plenum gives an example of how to fix it on a Passat.

[paul b]

yep, hagis is right. There was a recall about it on some A6s, but I don't know if there was one or what the criteria may be for a recall on an A4.
Paul

[Jonse123]

Thanks Paul & Hagis,
checked under the battery today & although there were a few leaves I poured water into the drain & it flowed easily to underside of car but I can see how this could easily be another cause of flooding / shorting.
Checked my pollen filter & it definetly feels wetter in one spot so I reckon ( the wife reminded me ) I used warm water to defrost the windscreen a couple of times over the Xmas break & probably got water into blower & elsewhere.
Will leave to dry out the passenger footwell & I'll recheck the current draw from battery again next weekend.
Would still like ( need ) to know what the normal current draw is for this car with ignition off ( I only know mine is more than 250 mA at present as it blew the fuse in my 7 pound B&Q ammeter )

[jonbaker]

Mine qualified for the recall, going in tomorrow

[paul b]

So there is hope

[Jonse123]

Thought I'd give an update :
Pretty sure the reason for the battery draining was an electrical short caused by water in the passenger footwell area or the blower assembly.
Believe most likley route into the this area was via the pollen filter . Got by for a week by disconnecting battery when parked.
Have cleaned & applied silicone to the underside of the pollen filter housing & ensured the drain channel above the filter is sat correctly in the two clips .
Checked after 1 week & filter was dry. Have left the battery connected for over a week now & ( fingers crossed ) has been fine since.
Tried checking the current ( amp) draw with ignition off & it is still greater than 250mA ( the range of my cheapo ammeter ) but I guess it might be normal...
Anyway all seems OK now.

[hagis]

Glad to hear!