something's draining the battery!

hi all, a bit of an arse my car's become and once it's fixed i'll love it again

basically something was draining the last battery and it eventually died. wouldn't start, and there was no point in jump starting the car as i'd need to do it again the next day etc.

so i changed the battery and all was ok until a few months after. now the car's died the same way.

it's been really frustrating as i'm not really that technically minded but i'm starting to suspect the fusebox for some reason. i can see that water has got into the car from either under the scuttle tray or from inside the door panel. the passenger side carpet is soaked and so is the rear passenger side. may it also be the alternator?

i have half a mind to just drive it into a restoration place and tell them, just rip it out and rebuild it but sense tells me that the problem is more easily fixable and substantually than that.

does anyone have any ideas as to what may be going on?

thanks

andoni

Have you had your alernator checked,if so best thing to do is check any perminant live feeds,do you have anything running off of a perminant live like electric windows or anything like that where the switch can stick also ive noticed another thing to drain the battery is the heated rear window i know it works with  ignition on but  ive had times where this has drained my battery down so i try not to use it too much, failing that it might be worth changing the fuse box if you can get another second hand one, its not too hard to change ,if your unsure then take a photo with a digi camera if you can so you know where all the plugs go

Yup, I'd look at alternator first off, make sure it's charging properly.

On the leak front, first, make sure the drain holes each end of the scuttle area are clear and free from crap as this is common (and cheap fix!) reason for the wet floor (to name but a few!) Worth checking before you hand the car and ??? over to someone else.

Check also your sunroof drain tubes are doing their job (assuming you have a sunroof!)

You can see if there is a constant drain on the battery when the ignition is off, by removing the negative lead from the battery and joining it back to the battery through the Amps circuit of a multimeter.

With the clock, radio (memory) and any immobiliser connected, you should only see consumption of about 0.05 amps - any more should be considered as a fault. If you find that there is a higher reading (a current "leak"), try removing each fuse in turn, to see if the leak goes away, then you can examine all of the items that the fuse protects.

I used this method to discover that the radio in my car was itself faulty, and even when it was turned off, it was consuming power (0.3amps - enought to drain the battery in about 3-4 days).

I got the radio fixed (faulty diode in the power circuit they said), and everything's ok now.

My golf had a complete lack of life in the outside lane of a 6 lane traffic light junction two days ago…..it looks like my alternator is gone.

Can anyone tell me how to check with a multimeter just to make sure before I go and get a new one??? Or is it easier to just get a recon one??

Hi Tom
         firstly if it's faulty it will be on an exchange basis with your supplier to buy new would be very costly  .
         To see if it's charging use a Digital multimeter set on volts DC up to 20 volts , connect to the battery with out the engine running and you should see 12.25 to 13.5 volts , then leaving the the meter in position start the engine and run at 2000 to 3000 revs for a few seconds allow to tick over and you should see at least 14+ volts . The 14 volts is the current from the alternator and shows that you have a basic charging current to the battery from the alternator . Then do the same test with all the lights on , the alternator should still be capable of putting out at least  14 volts .
        If none of the above suspect your alternator if you have charging current suspect your battery .
          This is of course after checking the obvious fan belt , alternator connections and battery terminals .

cheers Chudd….

Thanks Chudd, I'll check those points out this weekend.

I took the battery into Halfords a few weeks ago and they said it was not holding charge, so I bought a new one and it's done the same thing….me thinks I was robbed at Halfords.

Thanks for your help.

Also check out this web site : http://www.vtr.org/maintain/alternator-overview.html


Cheers Chudd….

Tom said

I took the battery into Halfords a few weeks ago and they said it was not holding charge, so I bought a new one and it's done the same thing….me thinks I was robbed at Halfords.

Don't condemn them just yet - your old battery could have been knackered from being run almost flat a lot, due to a dying alternator, or "leaking" circuit, so it failed their test, and the new battery is going flat for the same reason, (and will also become knackered soon enough, if you don't find the source of the problem).

…or they could have just robbed you !  :wink:

I've looked in the trusty Haynes manual for this but can anyone tell me how much play I should have on the alternator belt??

I seem to remember seeing this info many years ago on my beetle Haynes book but it doesn't seem to be in the golf one. I guess there should be an optimum amount of movement in mm on the belt??

Thanks,

I aways set vee belts for dynamos and alternators with +/- 0.5 inches flex on the longest length.  force to apply is about 3/8ths of a grunt.