VW transporter battery draining

[CornishPete]

I have a 2005 VW transporter 1.9 and the battery is draining when parked. Will jump/bump start ok and once running it will start and stop like normal for a rew hours and it's showing 14.4v once engine running so the alternator appears to be working. If it's left 8ish hrs or more it's drained though. It's got a new battery as that was my first thought!

Are there any typical culprits for draining a battery like this? If not where would I start looking?!! Could be a needle in a haystack job!
Thanks in advance.

 

[minimutly]

Yes, alternator will do it. Put your hand on it to feel if its warm. CD players are known to do it too, interior lights?

 

[carter13]

Have you got a multi meter ? if so check for a parasitic draw, if draw is too high pull one fuse at a time to find the culprit.

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[CornishPete]

Yes, alternator will do it. Put your hand on it to feel if its warm. CD players are known to do it too, interior lights?

I'd assumed it wasn't the alternator as battery shows 14.4v when the engine is running, that and once it's been running for 5 minutes it then will restart without problem so presumably the battery has recharged in that time?

 

[Ruffian]

Leave the van and check the voltage prior to starting, that way can figure out if looking for dead cell in the battery or parasitic drain.

Would be checking for drain anyways as easy test to do with a basic multimeter and once confirmed low amperage draw (sub 0.05 amp) then can say that's normal usage for the alarm system.

Check the age of the battery/condition also as could be something simple.

 

[colnerov]

Disconnect the alternator overnight, does it still do it? If so, there's a diode gone bad in there.

 

[Migmac]

Sound like the same issue my nephew has, it’s his radio that is draining the battery in his transporter.

 

[Hotstuff]

There are some good guides on YouTube regarding parasitic drain problems on cars.

Good luck with your mission.

 

[citizen kane]

I had a similar issue, not sure if yours has a webasto heater, mine would randomly turn on and flatten the battery, I only tracked this down when I walked passed it one night and heard the heater running

 

[Nomad]

I've played this game too often ...

Go for a drive to charge the battery, measure with voltmeter - disconnect a battery terminal - recheck voltage the next day - if it's down the battery is scrap ( beware - do you need radio codes etc if you disconnect the battery?), if it's about the same the battery is ok and something else is the problem.

Use a multimeter to check amps / current when you connect the battery with ignition off with all doors closed so no courtesy light (expect a small draw for alarm, central locking etc).
If high, pull each fuse in turn to see which circuit is taking the power and go from there.

Has any wiring been changed recently? Any new gadgets added? Top suspects are radio or a courtesy light staying on (check the one inside the boot!).
Hope it works out, keep us updated.

 

[CompoSimmonite]

Disconnect battery and leave overnight. Reconnect battery in morning to confirm not a duff new one It's happened to me !

 

[finyuk2005]

I had a similar issue, not sure if yours has a webasto heater, mine would randomly turn on and flatten the battery, I only tracked this down when I walked passed it one night and heard the heater running

that could be the case temperature sensor gone bad, certainly with the chinese knock off heaters that will turn the fan on because it thinks its too hot

 

[awemawson]

On my Discovery 2 one of the electronic units (ecu or maybe cody control unit) was waking up and drawing power of an amp or so before going back to sleep quite a while later. Turns out every time my electric gate opened it transmitted an RF signal to an alarm and woke the Disco up !

 

[finyuk2005]

how on earth did you finally figure that out?!

 

[brightspark]

a dc clamp meter would help if its drawing current . when not running clock the amperage draw and if any showing start pulling fuses to see if it drops and what its on

 

[awemawson]

how on earth did you finally figure that out?!

The RF was also swamping the remote key fob so I had a bit of a clue to work on. I still have to wait for the gate to fully close before I can lock up !

 

[nickk]

On my Discovery 2 one of the electronic units (ecu or maybe cody control unit) was waking up and drawing power of an amp or so before going back to sleep quite a while later. Turns out every time my electric gate opened it transmitted an RF signal to an alarm and woke the Disco up !

Opposite where I used to live was a fuel station,every modern LR that pulled in had alarms going off,then the vehicle wouldn’t start,all had to be towed out unless they were lucky and could fix it.