Lupo Battery Drain Ideas???

[eyechronic]

Ok I bought a lupo recently and I'm new to the forum, Bought the car off a bit of git everything seemed fine when i test drove it started perfect ran well ect..

Only when a week or two after having it parked up at home i discover somethings draining the battery and i've no idea what? thought it was the battery first so got a new one and still have same prob,alternator is charging the battery after getting a jump.. its a case of if left over night battery is almost completely dead or day & 1/2 totally dead... odometer seems to stay on with key out of ignition, radio turns off ect? Any Ideas please??

[Mike_M]

Is the stereo aftermarket or original. Might be worth seeing if an aerial booster has been added but connected to permanent live and not switched.

[NOCK]

I've read before that the window switches can cause this? Not sure whether VAG-COM would show anything unfortunately...

[eyechronic]

Is the stereo aftermarket or original. Might be worth seeing if an aerial booster has been added but connected to permanent live and not switched.

Hey Mike,

Stereo is the original blaupunkt..I had taken the fuse out overnight before to check but same prob, I've had a look at the aerial this morning and all seems to be standard as well, It's a bit of a puzzler only thing I can think of is the odometer but I seriously doubt that would be enough to drain a full battery and plus I had a golf for a few months before this and it stayed on constantly? hmm?

I've read before that the window switches can cause this? Not sure whether VAG-COM would show anything unfortunately...

No electric windows here unfortunately mate.

[treblet]

Battery clamps done up tightly?

Sounds silly but I had a slightly slack clamp on mine as it had cracked and was struggling to charge the battery fully but when checking it with a multimeter it looked okay.

[eyechronic]

Battery clamps done up tightly?

Sounds silly but I had a slightly slack clamp on mine as it had cracked and was struggling to charge the battery fully but when checking it with a multimeter it looked okay.

yeah mate it's charging the battery no problem when its running, I've had to start using it now so I'm taking one of the clamps off the battery now every time I park up for a while... which as it sounds is a bit nuts!?

[7upo]

Corroded terminals somewhere? Maybe in fusebox? A relay getting stuck on (I.e glow plug relay?)

[John West Bear]

Got the same problem with mine at the moment. Will let you know when I know what it is - VW are trying to find the fault at the moment - Free of Charge as they have cocked up a few things on the car.

[millsy12]

i had a polo 6n with a similiar problem and it turned out to be the earth from the battery to the body of the car had corroded. this may help. ??

[Ben™]

I had this problem.

Left it on a battery charger for 24hrs and it worked perfectly.

Turned out to be the weather, had left the battery just enough to start... sometimes.

[Damogti]

Hi This drain could be anything! I work in a garage and when a vehicle comes in with an electrical drain the chap who does all the major electrical work basically connects a device to the battery , not a multimeter before you ask! anyway the drain should be no more than say 1v not sure what it is but say it had a drain it would be high value and what you do is remove a fuse at a time and watch the metre and finally when the drain drops you check what the fuse is related to and thats the fault! When im back work on wednesday il find out what its called and correct volt drain you want if i remember the kit isnt cheap tho! Sorry if it dosnt make much sense hard to write down etc!

[John West Bear]

I disconnected the Negative terminal and using a multimeter put one probe on the Battery clamp and the other back on the terminal of the battery this shows a drain of 0.05A (50mA) I went round and pulled fuses one by one and located to be a fault on the alarm circuit / immobiliser / CL circuit. When this was removed the load dissapeared. Now always had a bit of an issue with the keys and the remote locking so that is being checked at the moment.

I have also checked to make sure the alternator is charging correctly and getting 13.56v at idle so this suggests its working OK. (Could be higher I suppose!) this was with all electrical equipment off - Only thing going was the enginer (No Lights / Radio / etc).

Took the Radio out completely and found a broken cable however I don't think this is going to have much impact as its not a Perm live but I have crimped this anyways to stop it touching any chassis parts. Also found old RCA leads down the back of the radio so these are coming out as well.

Also checked the ECU plugs were in as tight as can be they were a little loose - So pushed these back in as tight as I could.

Only other thing that I have noticed is the Junction box for the GTi where they have relocated the battery to the boot has a corroded negative lead (Corroded as in its not clean metal and has some surface rust. So will check battery in morning and if its still playing up then will get on that as well.

That is about as far as I have got - Got to admit Battery drain issues are a total ballache.

[chris27]

Did you do the current draw test with the car open or locked? Have you called up VW or a specialist, or checked in any workshop manuals to find out what the manufactures specification is for closed circuit current draw?

[John West Bear]

Doors Shut.

Today went round and tightened up connections to starter motor.

Removed old stereo wiring that was previously there as VW were adamant that had something to do with it so removed it for them as 1 less excuse.

Removed the Gamma Stereo that was there and CD player.

Checked earth from Battery to Body - All tight.

Did check the missing part of the alarm cable as well to see if there is voltage or if this had been disconnected - There was 12v here so is it possible this could be causing the problem?

The remaining part is missing completely but is part of the loom that detects whether the bonnet is open or closed?

[chris27]

Doors Shut.

Did check the missing part of the alarm cable as well to see if there is voltage or if this had been disconnected - There was 12v here so is it possible this could be causing the problem?

If its just the plug connection there then there isn't anything to draw current as its open circuit.

Is that doors just shut and not locked then? Would the current draw not be different with the car being locked? Could try this with the doors and boot open, just make sure you latch them over so the car thinks the doors are closed and hit the little button near the drivers seat to turn of the interior sensors. If you can get the multimeter in series like you did before without breaking the contacts (as this would set the alarm off) it will then give you a accurate reading of what the vehicle is actually drawing overnight when you leave it.

And as i said before without manufactures specification, you don't have anything to compare your results to.

[Damogti]

i guess if you have found disconnected wires someone knows something about it? i dont know if this helps but my lupo gti had some troube with the alarm going off etc a few years ago and what it was , was the rear tail gate was leaking water not loads and water was going over the rear boot latch and was shorting out the plug on the latch, spreyed wd40 in the plug sorted the leak and all ok, also the rear washerpipe on the wiper motor on the boot can leak hence water leaking on the latch,

Also does every thing work on the car on the door all windows central locking speakers? if something isnt working right on eaither door check the wiring between the door and the a pillar, the platic coating can go brittle and break the wire,

Also when checking charge rate do it with all ligts on heated screen.

let us know cheers

[Damogti]

i guess if you have found disconnected wires someone knows something about it? i dont know if this helps but my lupo gti had some troube with the alarm going off etc a few years ago and what it was , was the rear tail gate was leaking water not loads and water was going over the rear boot latch and was shorting out the plug on the latch, spreyed wd40 in the plug sorted the leak and all ok, also the rear washerpipe on the wiper motor on the boot can leak hence water leaking on the latch,

Also does every thing work on the car on the door all windows central locking speakers? if something isnt working right on eaither door check the wiring between the door and the a pillar, the platic coating can go brittle and break the wire,

Also when checking charge rate do it with all ligts on heated screen.

let us know cheers

[John West Bear]

If its just the plug connection there then there isn't anything to draw current as its open circuit.

Is that doors just shut and not locked then? Would the current draw not be different with the car being locked? Could try this with the doors and boot open, just make sure you latch them over so the car thinks the doors are closed and hit the little button near the drivers seat to turn of the interior sensors. If you can get the multimeter in series like you did before without breaking the contacts (as this would set the alarm off) it will then give you a accurate reading of what the vehicle is actually drawing overnight when you leave it.

And as i said before without manufactures specification, you don't have anything to compare your results to.

It's just the plug nothing else. Which means that there should be no drain and there is no alarm connection to the bonnet. The doors are all shut and I have tested before with the boot shut and car locked still got the 50mA drain.

I guess not I have been told that it should be around 20mA and although were talking a very small amount the battery on the car fully charged only lasts 17 hours at a time so its significant.

i guess if you have found disconnected wires someone knows something about it? i dont know if this helps but my lupo gti had some troube with the alarm going off etc a few years ago and what it was , was the rear tail gate was leaking water not loads and water was going over the rear boot latch and was shorting out the plug on the latch, spreyed wd40 in the plug sorted the leak and all ok, also the rear washerpipe on the wiper motor on the boot can leak hence water leaking on the latch,

Also does every thing work on the car on the door all windows central locking speakers? if something isnt working right on eaither door check the wiring between the door and the a pillar, the platic coating can go brittle and break the wire,

Also when checking charge rate do it with all ligts on heated screen.

let us know cheers

I've found a couple of disconnected wires behind the stereo and also the plug under the bonnet these are all now crimped off or not connected and taped and the drain is still the same.

I've had no trouble with the alarm, Apart from it going off everytime I have to jump the car when the battery is flat but its doing its job ok. Yeah everything works fine which is why its a bit of a puzzle. All speakers work ok, window buttons are fine, locking buttons work on the doors.

I can check the charge rate tomorrow with everything on and see what that is. However it still won't solve the mystery drain.

Only another couple of things I can think of that is doing it is the alternator diode might have packed up and the alternator is draining the battery but that is an extremely long shot, Possibly Convenience Module (Anyone know where this is?) and last but not least maybe a relay (Although I would expect the drain to be a lot more if a relay was out). I mean at least no one can say I'm not trying to find it!

[John West Bear]

Bit of an update -

Disconnected the convenience module and the battery appears to be holding a charge fine. So would appear as though found the cause of the problem. 14 day Back order on CCM modules for the GTi from VW.

So will update again when new module in place.

[Damogti]

sounds good!

[John West Bear]

Update:

Finally got to the bottom of this.

The CCM has come in from Germany for the car which has all been fitted and coded to the car. I also done some Insulation Resistance tests on the loom when the car was apart and noticed the offside dooe was weak compared to the rest of the wiring so I have changed this at the same time.

The CCM was the main culprit. Car has been running a Week now with no drain issues at all. Previously was lucky to get 18 Hours out of it.

Lupo Battery Drain - Done.

I have listed Part Numbers for the bits I have replaced on the Car incase anyone else needs or finds them Useful

CCM Module: 1CO 962 258 N

Drivers Door Loom: 6X2 971 120 Q

Will update progress thread with some pictures of the parts fitted later today as well.

[scotty_82]

Nice fault finding.

Should write up a small back story and guide on how to go about fault finding this type of fault as a guide?

[ben16v]

where is the convenience module located??

[John West Bear]

Driverrs side footwell. Have to remove the Lower dash to get to it. Located roughly behind where the Fuseboard is for the car.

[ben16v]

john i`ve had a quick look at the car this morning, i can see a black box on the right hand side next to the relays mounted front to back, does this sound like the module? just wanted to check before i dig any deeper

cheers