Retro-fitters

[Johnny_tro]

Hi everyone. I have MK5 GT 2004 with most things upgraded - Canbus, CECM etc. I have lots of stuff fitted including RNS rear under seat lighting.

The battery drain has now become a JOKE!! 
I have had a local garage check the battery and altenator and they are fine. Battery is taking and holding charge and the altenator is giving out.

My battery drain is now daily.

Please help? should I just get new battery and altenator (guessing can upgrade these?)

Getting really  and  of this

[skard]

Has it started draining only since the RNS510 was put in?

If you take the stereo out and put your original HU in, does the problem still persist?
If it does I would suggest the issue lies with a wiring fault elsewhere, if the fault goes away with the old stereo in place then I'd focus on the stereo itself - has it got a shutdown issue that's physical or firmware related etc.

I can't help with this though as I've never had a newer generation OEM HU.

Maybe a list of your installed modules (if attainable) would be a good start for people helping you. For example what par number does your new CAN gateway have?

[Johnny_tro]

Is was OK, maybe once a month this happened since the RNS B version was installed.

Now I have the F/H version one, and added more retro fits it has gotten worse  All parts are genuine OEM and are standard plug and play looms - so wiring wise should not be an issue at all.

Canbus < think it ends in AB if I remember correctly, again brought off a chap on here who knows his stuff.

The obvious << more stuff you add the more strain you add on the car, but surely the altenator should keep things in check. I can drive for half hour, stop, instantly try and re-start and its dead :(

[skard]

Tested the starter motor?

Checked your main earthing points?

Few years ago I had intermittent starting issues caused by a dying engine ECU, mimicked a dead battery.
Does a scan show any communication errors?

[Richn83]

Think new battery would help go for a bigger one than standard higher cold crank and more ah that us the same size would help.

[Johnny_tro]

So look for a battery with a higher 'cold crank' ? know all batteries have standard 'V' but guessing they have ratings etc on the side or something?

If something is sucking the life out of the battery, you think this should be my first point of call? not cluded up on batteries.

[skard]

Can you get use of VCDS???

It will tell you any faults, errors, and if left plugged in wil monitor battery voltage to see if it drops quickly.

Really speaking, it's just guessing until you can rule out certain things.

I'd say a bigger rated battery will not make it an worse, but if it refuses to start immediately after a drive then it can't be battery capacity being lost!
In my experience you're looking more at a bad earth, faulty ECU or dodgy starter motor.

Take it to an auto electrician rather than a normal garage.

[Johnny_tro]

Can borrow a VCDS - but would not know where to start, just about manage a few basic codings.

I need VCDS Plus someone to use it lol

I believe you can do a 'driving test' - takes about an hour where you drive around and VCDS will check for faults?

Cars had full service new clutch etc. it has NO codes showing. Only issue I have is airbag light being on (as I remove the seats) so need this resetting at some point.

[jason_rmh]

Might be worth checking courtesy lights in the glove box and boot to see if they stay on when the lid / boot is shut?
I had a boot courtesy light causing battery drain on one of my older cars and took me a while to figure out.

Worth a go? Although I do not think this would drain the battery on a daily basis.

Anything that won't allow the CAN bus to go to sleep will drain the battery.

You can also test for battery drain using a multimeter:
Ignition off and key out of ignition.
Set multimeter to amps on DC unfused setting.
Remove positive battery cable.
Put black probe on the now loose positive cable and the red probe on the positive battery terminal.
The multimeter will now carry the current and show any current being drawn on the display.

WARNING: Do not test for prolonged periods as this will melt the multimeter, but ok for short tests to determine battery drain.

A good way to show this is to get someone to open the door while you monitor the current and you should see the amps shoot up as the interior light come on.

When you have a reading for what your drain is, start pulling fuses one by one until the drain goes away, you will then know which circuit is causing the drain.

Im not sure if pulling fuses wakes up the can gateway, invalidating the test, so hopefully someone can advise on that?

EDIT: Found this which show a technical service bulletin on how to monitor battery drain on golf / jetta:
http://forums.tdiclub.com/showthread.php?t=312511

Hope this helps.
Jas

[Johnny_tro]

thanks for the info. Anything i can try is a help. I will give this a try and read that link. Can and cecm are all new and updated which was done to sort any light issues and rns drain, well was supposed to. Will try some of this think one of the lads at work has a tester