Scared to leave my car

[Tornado GTI]

Hi all hope you can help, I have a MK2 GTI 16v 92 and I have my first problem ☹. I have been using the car very little recently only driving about 25-30mins a day. The problem started when I went to start the car one morning and it wouldn’t start, the battery is about 3 months old I think so my first thought was I am not driving it for long enough for the alternator to charge up the battery.  I charged the battery up, fitted it back to the car and it started first time. It has been working for about 3 days with me driving for a longer each time. But there are the same signs starting to happen again with the car e.g. when I turn the ignition over the car has a problem starting, like it wants to stall. Most of the time it works but other times I have to rev it a little bit. I went to the garage to check the battery today and the man told me it was fine and he also said it would not be the alternator because the battery would have died by now?

Does any one have any ideas what it could be?       

[Diamond Hell]

Possibly your radio.  Depending upon the connections this could well be sucking power out of the car gradually.

You need to go through the fuse positions with a multimeter looking for the current draw with the ignition off.  Find it and you'll have resolved the issue.

[Thom89]

Possibly your radio.  Depending upon the connections this could well be sucking power out of the car gradually.

You need to go through the fuse positions with a multimeter looking for the current draw with the ignition off.  Find it and you'll have resolved the issue.

This....

But before you break out any kit, just check that the boot interior light, and the glovebox light are not illuminated while the car is not running, could be that simple.

Thom

[pigbladder]

get a cheap multimeter , you can check if the alt is charging and if anything is causing a drain

my first thoughts would be the alt is on its way out

[rob.043]

I heard that a faulty alternator can drain the battery too when the engine is not running. 25-30 mins of driving a day should be plently to keep a battery going, unless you are using lots of electrics at once. i.e. stereo, lights, wipers, fan etc, may be a bit much on low engine speeds, say just driving around town. but I suppose a healthy alternator should cope.

as mentioned above, check fuses for a drain, but a drain may be hard to find. An alternative/start point would be to disconnect the battery after using the car, and connect it just before you start it. A bit of a pain yes, but it will ensure there is no drain on the battery and if the symptoms disappear, then you know to look for a drain, and not a new alternator!

I had a similar problem with a mk2, unfortunately the car was written off before I solved the problem! 

[DOA]

Check the alternator belt tension too, I had a combo of lack of tension and radio current draw on mine that gave the same symptoms (doesnt help that the starters lazy at the best of times and sticks in cold weather but I CBA replacing it).

[dadrathers]

I agree with Rob043 25-30 mins should be plenty to recharge the battery after normal start (with an alternator) - most of you guys won't remember dynamos but they were pants at charging especially on tickover (Thom??).

I like the idea of disconnecting the battery as a 'test' - bit of phaff but will isolate the issue.

[X4MGS]

as said get a cheap Volt tester/Multimeter and make sure your getting at least 13.5-14V to the battery on tick over, if not then it's a process of elimination... Belts, Voltage regulator etc etc

There is a way of testing for battery drains by using the Ohm's setting on the earth leads - can't exactly remember how but I'm sure a 10 min search on google will through something up!!