Hello;

Bought a 2nd hand 1998 Octavia 1.9tdi last week. Tried to start it one morning and the battery has drained flat - AA check it and alternator isn't working properly, so I had it replaced. Anyway, this was a couple of days ago, it's had a couple of long (200 + miles on motorway) runs since then, and when I went out to start it this morning, battery is dead again.

Any ideas? Is it likely there is a drain on the battery somewhere? Will a new battery be needed?

It's got the original tape player in it, and no modifications...

CHeers

Dave

Hi David

I actually have the same problem on my 2000 TDI SLX, except that after putting off buying a battery, i eventually went out and spent £80 on a new battery and the problem still persists, I only logged in to Briskoda today to see if anyone had any experience of what it could be.

With hindsight (and if i were you) i would try disconnecting the battery overnight and then see if it starts next day. ie. as you park the car one night and you know that the battery has a good charge in it disconnect the earth lead (it's only a 10mm spanner)then next morning reconnect the earth lead and if the car starts it suggests that it's somehow discharging overnight, then the tricky part is finding out where.

Does anyone else have any experience of overnight discharging (OOoo eeerrr) to try and save myself and David some time.

Many Thanks

Frank

There are three possibilities here:

1. Battery is discharging overnight.

Take Frank's advice and disconnect the battery overnight.

Make sure everything goes off with the ignition (i.e blower, heated rear window, etc)

Try leaving fuses out. The ones I'd try first of F37, F38, F5.

2. Battery is dead.

Many battery suppliers will offer a free battery test.

3. Battery is not being correctly charged.

The original alternator was OK. A problem with the D+ connection to the alternator can cause it to charge incorrectly/intermittantly. The D+ is the small blue wire coming out of the alternator.

Ok, here's the thing..

I'm currently charging my battery. However, I noticed when I took out my keys and locked the door that all the display is staying on. I attempted to turn the radio on with no keys in the ignition, and it worked... presumably it shouldn't and there is a serious wiring fault here.

So who should I call? Auto electrics? It was a local garage that put the alternator in - I was going to take it back to them tomorrow but if you don't think that they would have the expertise (non-skoda specialist) I won't bother. I'm not good with cars, know the basics really, and just want to go to the right place which gets it fixed the quickest.

Cheers

Dave

Do not worry, the oddometer display is on all the time,and yes it is possible to turn on the radio with the ignition off.

An old trick to find find what is discharging the battery is to lift the lead off the battery and connect a 12v bulb between the lead and the battery post.If the lamp is on something is drawing current,it is just a matter of removing fuses till the lamp goes out.

Try pulling Fuse F37. With the small fuses at the top of the fusebox, it's the bottom of the middle row of larger fuses. The radio, central locking, etc, should be off when you lock up the car. This will confirm it is the 'S' circuit that is left on when you remove the key.

Even if you intend to take it somewhere, try and do as many tests as possible. It will give valuable information to whoever is going to do the work and save time/money.

Hi...

Thanks, I'll try some tests tomorrow. At the moment the battery is charging, so hopefully I'll be able to try some things.

One thing I don't completely understand - if I pull fuse F37, and everything goes off, what exactly is that telling me about the drain?

Excuse my ignorance - just keen to do what you guys are saying and have as much information to hand as possible. Someone somewhere else did say that if the battery is allowed to completely run down a new one would be needed..

Cheers

David

There are various different circuits that depend on the position of the ignition key. The 'S' position is where the key is in the lock but off. When you pull the key out the radio, etc, turns off. I've seen a few problems with the 'S' circuit not going off. Problems with circuits associated with other positions tend to be more obvious (acc, ign, start).

If the battery doesn't drain overnight, it is something on the 'S' circuit or the switch.

Ok.. thanks, this is very useful stuff. I think that's what I meant before - if I get in the car, without putting the key in, I can still turn the radio on etc - so that would probably signal a wiring problem with the 'S' circuit, wouldn't it?

Ok.. thanks, this is very useful stuff. I think that's what I meant before - if I get in the car, without putting the key in, I can still turn the radio on etc - so that would probably signal a wiring problem with the 'S' circuit, wouldn't it?

No, you can turn the radio on with key in or not. If the radio does not go off when the key is withdrawn there is a prob. HTH

Hi!

My car is a 2000 model. I changed my battery last year - it did not take enough charging. A cell that had gone bad.

Modern batteries do not last as long as 20 years ago. One of the causes are the decrease in space below the lead-cells, which make them more vunrable to shortcircut as flakes of lead falls of and sinks to the bottom and piles up..

1. But first try washing the top of your battery. You would be surprised how little dirt it would take to shortcircut your battery.

2. Disconnect the battery - and then charge it. Measure it when fully charged. Wait for some hours and measure again. If the voltage drops, you probably need a new battery.

You could also buy a "ballon" to measure the acidweight in the batterycells, which tell you exactely which circut that is shortcircutted.

3. If the battery holds the voltage, you probably have a shortcircut in the electrical system. How to find this is well described in other posts on this tread.

Olit

Hello;

Thanks for all the advice..

The problem eventually seems to be resolved. I had the AA out, and he checked the battery, and it was taking charge no problem, and holding it. There was, however, a 2amp drain..

Took it into the garage, who found that some monkey had put a wire straight from the starter solenoid to the battery, holding it open...hence draining down overnight. They removed the wire - and it seems to be fine.

However, it would say this.. in the morning, it is still a little reluctant to start. It does start, but it's by no means immediate, and always makes me a little...worried.

Should I just put this down to the car being 10 years old, or could it be a starter motor thing?

Cheers

Dave

My brother's taxi (1.9 110 TDi) has the same problems, never have got to the bottom of it. Only causes a problem if he has a holiday and leaves it for a few days when invariably it won't start as battery flat. Sounds like the same problem though, usually reluctant to start (but does) and a mysterious battery drain.

If anyone knows the answer - they get a virtual gold star!

Hi again!

Hmmm - it was a 1998 model diesel you got.. Is it a 90 or 110 hp? Mileage? I am sure you will get help here.

I have little experience with this engine-type, but I would check the glow-plugs and maybe put some injectorcleaner in the fuelsystem.

And last but not least - get the MAF properly checked! I persuaded my neigbour to get this done on his 99' TDI Octy as service also was due. The VAG-garage reluctantly said they should do it.

Boy was he in for a surprise! He had been driving with a faulty MAF, probably since the car was next to new!! Suddenly the car went much smoother, and felt much stronger. He even started to regret he had ordered a new Roomster, but it was to late to cancel that...

Olit

OK I've been doing some testing on mine, connected ammeter between battery and lead, have a reading of 0.4-0.5A pulled all the fuses one by one, and fuse 14 seems to be the offending item, central locking and interior light (interior light was turned off for test, reading went to 2.5A when turned on) any ideas where to look next. If i re-connect the battery and pull the fuse i can hear a relay click behind the dash.

Any help appreciated

Fuse 14 feeds the convenience controller which is behind the panel with the headlight switch on it.

Did you have the door open or unlocked? When you close and lock the door, items such as the timed feed for courtesy lights go off.

Door was open, i will try again with it locked.

Many thanks

Frank