Electrical drain problem

jamesditchy · Post by **jamesditchy** » Thu Feb 23, 2017 6:28 pm

Just had the car in to the auto electrians to have the nav and cd changer sorted. He repaired a damaged cable and all was working well. Next day the battery was dead. Tried the battery off the other zed and the next day the same.

Took it back in and he said the nav and cd changer are drawing 1/2 amp with no key in ignition. He suspects they're both faulty. Seems odd that both go at the same time. Anyone had any problems like this. Cheers Jay

bladeowner · Post by **bladeowner** » Thu Feb 23, 2017 7:02 pm

Not 100% sure but the car does remain live for 15 or 20 mins after switching off - did he wait? Maybe the Nav and CD changer are still live. Seems odd that they both would be faulty. I know somebody on the forum who's Gaptech module went faulty and was causing battery discharge.

jamesditchy · Post by **jamesditchy** » Thu Feb 23, 2017 7:20 pm

Thanks. That's some dismantling to get the cd changer out.

Scooba_Steve · Post by **Scooba_Steve** » Thu Feb 23, 2017 7:34 pm

Can you not just unplug them to see? Or pull the respective fuses?

jamesditchy · Post by **jamesditchy** » Thu Feb 23, 2017 7:46 pm

I have unplugged them for now but I'd like to get everything working really

peteslag · Post by **peteslag** » Fri Feb 24, 2017 9:48 am

If you can get your hands on an electrical multimeter I can walk you through the fault finding process. It is called parasitic drain, easy to fault find but you need a multimeter. You allow time for the car to power down and connect the multimeter to measure amps. Then disconnect each suspected faulty item one at a time until the current draw goes away. I find it hard to believe that your sat nav and CD changer are both goosed.

I wouldn't allow your battery to fully discharge again, car batteries don't like being fully discharged and recharged. They wear out in no time.

Scooba_Steve · Post by **Scooba_Steve** » Fri Feb 24, 2017 11:53 am

jamesditchy wrote:I have unplugged them for now but I'd like to get everything working really

And has that stopped a repeat of the drain? If so then it narrows it down, just try each one in turn next. Then it's hunting with multimeter time.

jamesditchy · Post by **jamesditchy** » Fri Feb 24, 2017 1:30 pm

Cheers Pete. I've got a multimeter so that would be great if you could tell me where to test. Jay

peteslag · Post by **peteslag** » Sat Feb 25, 2017 1:17 pm

Have a look at this:

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

In VERY basic terms, your car is using energy when it shouldn't, this is why the battery is draining. Current is energy, voltage is the pressure that pushes the energy down the wires and through the components. To measure this energy you need to put the multimeter into the circuit. This is why you have to disconnect the battery and connect the multimeter in between the the battery and the cars wiring. You don't need to pull each fuse in turn as it says in the wiki guide, just disconnect your sat nav and CD changer in turn and monitor the current levels. When the current drops down to an acceptable level you have found your culprit.

As said previously most modern cars need a bit of time to go fully to sleep, I would leave the car for 30 minutes after disconnecting the battery to let this happen.

If the sat nav or CD changer isn't causing the problem all is not lost, just let me know and I'll walk you through the next stage of fault finding.

jimbo1958 · Post by **jimbo1958** » Sat Feb 25, 2017 2:50 pm

bladeowner wrote:Not 100% sure but the car does remain live for 15 or 20 mins after switching off - did he wait? Maybe the Nav and CD changer are still live. Seems odd that they both would be faulty. I know somebody on the forum who's Gaptech module went faulty and was causing battery discharge.

I'm Still having nightmares over it Dave.

Here's a link OP......might help. viewtopic.php?f=3&t=67952&p=1000783&hil ... c#p1000783
Good Luck with it.

bladeowner · Post by **bladeowner** » Sat Feb 25, 2017 2:55 pm

jimbo1958 wrote:
bladeowner wrote:Not 100% sure but the car does remain live for 15 or 20 mins after switching off - did he wait? Maybe the Nav and CD changer are still live. Seems odd that they both would be faulty. I know somebody on the forum who's Gaptech module went faulty and was causing battery discharge.
I'm Still having nightmares over it Dave.

Here's a link OP......might help. viewtopic.php?f=3&t=67952&p=1000783&hil ... c#p1000783
Good Luck with it.

..And i got a free working battery

jimbo1958 · Post by **jimbo1958** » Sat Feb 25, 2017 4:02 pm

bladeowner wrote:
jimbo1958 wrote:
bladeowner wrote:Not 100% sure but the car does remain live for 15 or 20 mins after switching off - did he wait? Maybe the Nav and CD changer are still live. Seems odd that they both would be faulty. I know somebody on the forum who's Gaptech module went faulty and was causing battery discharge.
I'm Still having nightmares over it Dave.

Here's a link OP......might help. viewtopic.php?f=3&t=67952&p=1000783&hil ... c#p1000783
Good Luck with it.
..And i got a free working battery

So you did.

jamesditchy · Post by **jamesditchy** » Sat Feb 25, 2017 7:20 pm

Thanks for the replies. Gonna have a go at it tomoro. Just want to check. With battery disconnected, where do I test from. Across the disconnected battery leads or across the components themselves. Also if checking on the V setting on multimeter, what reading should I be achieving before testing and how long will it take for it to start registering a drop. Thanks Jay

Smartbear · Post by **Smartbear** » Sat Feb 25, 2017 7:27 pm

You should put the meter between the lead you have disconnected & the battery post you've just removed it from, the meter needs to be on Amps not volts

Rob

jimbo1958 · Post by **jimbo1958** » Sat Feb 25, 2017 8:05 pm

Smartbear wrote:You should put the meter between the lead you have disconnected & the battery post you've just removed it from, the meter needs to be on Amps not volts
Rob

+1

IIRC I clipped/wedged the test probes to the lead and battery and closed the boot with the meter hanging outside.
Also make sure you give it 15-30 mins before taking readings as IIRC it takes the car that long to go into "sleep" mode.
Also disconnect any aftermarket tech you might have installed......dashcam,intravee,Parrot,Gaptech, Bluetooth etc.
Good Luck.

Z4-forum.com

Z4-forum.com