Help!

[Elch]

Hi all, I wonder if anyone can help me?

Came back from holiday last week to find my 2003 Mexican Beetle's battery completely flat. It wouldn't recharge and was ropy anyway, so I bought a new battery. Car then started and ran perfectly.

Then I went away on business for 2 days. When I came back, the same had happened again: my brand new battery was almost completely flat after only 48 hours.
I've checked around the car and am certain nothing was left switched on that could have drained the battery.

Any suggestions anyone? Short circuit somewhere??

Cheers!

[phade]

Hiya Elch,

It sounds like that it could be any of the following:-

- Alternator not charging the battery and the alternator warning light bulb holder corroded.

- Immobiliser drawing too much current (but I think Manfred and others on here may know more about wether the immobiliser could cause this fault since my car does not have one).

Without really knowing what was fitted to your car it's difficult to tell what could cause your battery to go flat in 2 days. My car has never had that problem and I have had it since new (8 years ago).

Good luck with finding what's wrong with your car.

Regards,

Phil

[Elch]

Hi Phil,

Thanks for your suggestions. Have tried a few things and would value a 2nd opinion!

- with fully charged battery, am reading 13.8V across battery with engine running, and 12.7V with engine off.

- I disconnected negative lead, set multimeter to amps and put it in between battery negative post and car's negative lead. It shows a drain of 0.9A (ie quite a lot!). I then removed each fuse in turn to see if I could identify which circuit was causing the drain: reading was same throughout, which suggests that nothing connected to the fusebox is causing the drain.

- I then tried disconnecting the lead that attaches to the side of the positive battery terminal (circled in green on picture) - lo and behold, multimeter shows no drain at all with this removed.

What does this lead supply? It goes across the area under the back seat towards the left side of the car, then kind of disappears!

Any thoughts/suggestions appreciated!

[BigBadWolf]

Hi Elch,

had that problem several years ago when the battery of my girlfriend's Velvet Red was completely flat in the morning one day. After searching around a lot I found out it was the relay of the heated rear window (which had it switched on constantly). I don't know whether your beetle has got a heated rear window (perhaps aftermarket) but I would check that, too. In a beetle, there are not too many electrical gadgets that can draw current with the ignition switched off. Or did you leave the radio on?

Good luck with finding that problem!
Regards,
Peter

[Elch]

Hi Peter,

Sadly my beetle doesn't have a heated rear window. I tried disconnecting all the leads from the radio, but the drain is still there.

Oh well, the search goes on....

[Doc]

Hello Elch,
maybe it's a missfunction either of the alarmmodul or the immobilizer. Both are connected without fuses to PLUS.

The alarmmodul could be easily removed. It's place is under the frondhood above the fuses.

If thats your problem, let it removed and put a bridge from pin 22 to 23. With this line the alarmmodul cut's the ground connection to the fuel-pump-relay. You could see it in the picture here:


To remove the immobilizer is not so easy. It's place is in the left sidewall near to the ECU. You could open the black box and remove the plugs. If thats your problem, remove the complete immobilzer. To do this, you had to unsolder the 6 lines shown in the picture (marked red) and connect them in three pairs. The colors should be 2 x red, 2 x green/black and 2 x red/black or green/white. With this 3 lines the immobilzer cut's the connection to the injection-valves, the hallsensor and the ignition-trafo (did you say trafo?).


regards
Manfred

_________________
Register Nr. 336

[Elch]

Many thanks Manfred, I'll check it out!