MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Paulo P on October 02, 2018, 12:49:38 pm

Title: Mark 5 GTI battery drain issue, not the stereo.
Post by: Paulo P on October 02, 2018, 12:49:38 pm: Hi,

I have a bad battery drain on my Mark 5 GTI which is killing the battery in less than 2 weeks. At first I suspected it was the stereo and maybe someone had changed my head unit but found that it wasn't that.

With the car locked I can see this drain.

(https://farm2.staticflickr.com/1960/44139921245_460bd30efe_c.jpg)

Remove fuse F3 from the engine bay

(https://farm2.staticflickr.com/1945/31178586288_b6252d880a_c.jpg)

and the drain instantly drops to this

(https://farm2.staticflickr.com/1941/30115401047_c04936eb97_c.jpg)

A google search suggests that fuse F3 is for the multi function on the clocks, has anyone experienced this drain before and cured it?

Thanks :happy2:
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: Paulo P on November 01, 2018, 01:26:40 pm: Anyone come across this?
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: pudding on November 02, 2018, 08:35:24 am: It won’t be for the clocks at 20 amps! I’ve seen another reference saying it’s for the ‘onboard power supply module’ whatever that is!

I guess with that fuse pulled, figure out what no longer works on the car, or plug in a scanner and see there’s any power supply type fault codes.

Unfortunately F3 is not mentioned at all in the handbook.
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: Dogma on November 02, 2018, 09:06:10 am: How old is this battery?

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Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: Paulo P on November 02, 2018, 11:14:05 am: Quote from: Pudding on November 02, 2018, 08:35:24 am
It won’t be for the clocks at 20 amps! I’ve seen another reference saying it’s for the ‘onboard power supply module’ whatever that is!

I guess with that fuse pulled, figure out what no longer works on the car, or plug in a scanner and see there’s any power supply type fault codes.

Unfortunately F3 is not mentioned at all in the handbook.

I'll have to try that then, I was hoping that it was something that somebody had already come across. Thanks.
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: Paulo P on November 02, 2018, 11:15:36 am: Quote from: Dogma on November 02, 2018, 09:06:10 am
How old is this battery?

Sent from my iPhone using Tapatalk

The battery is about 8 months old, it previously killed a Bosch S5 in 10 months from new when it went flat unnoticed.
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: Paulo P on November 13, 2018, 04:49:04 pm: I've just got around to removing that fuse to see what stops working and it's the remote locking. With fuse F3 removed, the remote locking doesn't work and neither does the central locking via the drivers door lock. The central locking still works via the button inside the car though.

Has anyone got any ideas what part that could point at?
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: Paulo P on November 21, 2018, 11:26:52 pm: Anyone? I notice that the alarm LED is still flashing on the drivers door when I lock it manually which says to me that it's not the alarm that's causing this drain. A few years ago the alarm siren used to go off on it's own but it's not happened for years, even when the battery drains. I still wonder whether it could be linked to that?
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: muff1991 on November 22, 2018, 03:27:21 pm: could be linked... but not certain.

I knew someone whos battery would drain and it turned out to be the boot lid wasn't shutting off the boot light when closed. wasn't a VW but anything's work a check.
Title: Re: Mark 5 GTI battery drain issue, not the stereo.
Post by: mo on November 22, 2018, 09:02:38 pm: Apparently there are 2 identical relays in the engine bay fuse box that can cause battery drain if faulty.