Help, my car is sucking the battery dry!

Mon Feb 14, 2005 6:48 pm

My car had a flat battery last weekend after being stood for only 3 days without use. On friday I swapped the battery for a fully charged one while my local garage charged mine, they also did some tests and said that the alternator has been reconditioned at some point and is not quite charging as it should....but it wasn't too bad.

Tested with lights and heater on and nothing unusual showed up. They said that it was probably down to the alarm (although it was switched off when they did the tests). Car has been fine over the weekend but this morning it only just had enough juice to start....and I've just had to give it a push start to get away from work.

The alarm has been off since the 'new' battery was fitted so I was wondering if anyone has any ideas about what could be causing the drain. My central locking is also buggered and the control unit does have a tendancy to 'tick' repeatedly at times......but it's been out of action for about a month without problems till now.

Most of my driving is short runs but this weekend it had a few longer runs mainly without lights on, never with demister on, always with radio on.

Help!

Guest · Mon Feb 14, 2005 7:07 pm

see this http://www.e30zone.co.uk/modules.php?na ... topic&t=89

Lars

Mon Feb 14, 2005 7:22 pm

similar problem with mine turned out the battery was gone and wouldn't hold a charge.

Mon Feb 14, 2005 8:22 pm

Cheers Lars I'll keep an eye on that thread.

Chris, this has happened with two different batteries, my original one is no more than two years old.

Mon Feb 14, 2005 9:30 pm

hmmm if there's a problem with your alarm and the battery it seems like too much coincidence. it's worth checking/re-making all your alarm earth and switch points - my bonnet alarm switch caused this very same on mine a while ago - i had to slim jim my way in!

it's feasable that the alarm has been straining the battery for a while causing the battery to give up.

paul

Tue Feb 15, 2005 9:43 am

The alarm has been OFF the whole time that the second battery has been in.....so I don't see that it can be anything to do with the alarm.

Tue Feb 15, 2005 12:27 pm

You need to get a ammeter connect between the battery and the car to see what sort of current it is pulling in 'standby' mode.

Check the boot light goes out when shut, also check glove box light (i *think* this only works when the lights are on anyway...)

Tue Feb 15, 2005 12:39 pm

Yeah the boot light on my old cars did this and drained the battery. It took me ages to figure out what was causing it.

Tue Feb 15, 2005 2:37 pm

I drive a Touring so the boot light isn't the culprit.....but I'll check the glovebox light just incase.

Tue Feb 15, 2005 3:53 pm

Using a meter is the best way to do it really. If there is a current drain you'll see it straight away and then you can narrow it down by pulling out each fuse it turn to see when the current drops. I guess if you don't have a meter to could try each fuse each time you leave the car standing but it would take you a month to get through them at that rate seeing as there are so many and it wil be sod's law that its the last one you try

Tue Feb 15, 2005 5:54 pm

Can anyone tell me the type of meter I need to get my hands on in order to do these tests? A multimeter is what I'm thinking......but is there a brand that anyone can recommend as not expensive but up to the job?

Tue Feb 15, 2005 7:53 pm

You just need a multimeter meter that has a 'Ammeter' on it, Halfords do one i think for about Ãƒ”šÃ‚£12ish.

To run the test, disonnect the earth lead from the battery, and then place the black lead from the meter to the chassis, and the red lead back onto the negative terminal. DO NOT TRY to start the car! or turn on the rear heater etc, if you try to pull too much current, you'll blow the fuse in the meter.

With the meter connected, i would expect to see it pulling 100mA ish might be wrong there, never tried it on my E30. Can try it for you on my car if needs be, but it's too cold to go out there now!

If you are pulling too much current, start pulling out the fuses / relays and see which circuit causes the meter reading to drop.

Wed Feb 16, 2005 9:24 am

Nice one mate, I'll get myself to Halfords.......could be a long walk!

Will this meter also be useful for house electrics aswell or do I need a different tool for that job?

Wed Feb 16, 2005 9:36 am

Danstable wrote:Nice one mate, I'll get myself to Halfords.......could be a long walk!

Will this meter also be useful for house electrics aswell or do I need a different tool for that job?

House electrics? Have you not heard of the new Part P of the Building Regs? You are not allowed to do any work on your home, apart from change socket/light switches. All new circuits need to be done by a 'competant' person ie qualified.... that will be me soon!

Anyway, no a car multimeter is unlikely to be any use in the home. Most car multimeters only have dc voltage scales, you will need ac for the house.

Wed Feb 16, 2005 9:41 am

I had the same problem, left car for 3 days while out of country. Came back and the battery was dead and the alarm was activated, lights weren't flashing but I could hear it ticking under the bonnet. I jumped the car the following day and the alarm hasn't worked since, but the battery is fine. So as alot of people are saying the alarm seems to be a common fault

Wed Feb 16, 2005 11:28 am

mark

the part p is a pain for us 16th edition qualifieds - now we have to go back and do it all again. pah.

my 5 quid multimeter does household voltages and amps too...

i had a faulty alarm that was 'off' drain my battery completely dry overnight once. i pulled it all out in frustration and left the car immobilised and had to eat humble pie at my local alarm fitters....

paul

Wed Feb 16, 2005 11:55 am

Part P....pah, it's my fecking house, I'll kill myself if I want! Will get qualified sparky mate to check over any work I do before I come to sell the place.

Thanks for the help fellas.

Wed Feb 16, 2005 1:17 pm

Part P is there to protect you, the public & the insurance companies from bad workman ship. Policing Part P is almost impossible at the moment, but if you have a fire, and the investigation says its a electrical fault, and you don't have a valid electrical safety certificate, then if the future we may all find our selves with no home to go to. Will have to sleep in the car

Placey, didn't know you were a spark! i'm in my 2nd year of the CG2361...

Wed Feb 16, 2005 2:55 pm

"No Mr fire investigation dude, no electrical work has been done on my house since Feb 2005, that's why I have no certification." Job done unless they can prove otherwise.

Wed Feb 16, 2005 4:46 pm

Danstable wrote:"No Mr fire investigation dude, no electrical work has been done on my house since Feb 2005, that's why I have no certification." Job done unless they can prove otherwise.

So buddy, 'i've got a pile of ash that used to be a house' are you admitting to doing electrical work on your property between Jan 1st 2005 & February this year? Shame you just admitted that, better start saving for a new house! and whilst your at it, you had better start saving to pay the mortgage company back, have a nice day xxx

All for the price of a certificate (I wonder if i can sell certs on ebay with out getting caught?)

In reality, just do things right, hopefully we won't keep finding the sort of complete bodge jobs that 'mr man who has been to B&Q' thinks he can get away with.

Then get a competent electrician to test and certify the works.

Wed Feb 16, 2005 5:54 pm

I never admitted to doing any work on the electrics in my house!?!

I appreciate what you're saying about forcing poor workmanship out of the market, and I am all for that......they make my blood boil! But lets just say I worked as a sparky for 10 years before changing career, I now want to re-wire my own house.....but I can't because it will make my house un-sellable effectively. I am completely competent, it is my own house, I am not charging for my services, I think it is wrong.

Friendly banter.....always fun :lol:

Wed Feb 16, 2005 6:24 pm

I'm sure your allowed to 'replace any damaged cable' yourself. It just so happens that all the cables were damaged....

Of course you won't be able to change the db yourself, unless you say it was done before jan 1st 2005...

There is a backlash to this change over i know. Here in the UK we see our home as our castle, we can do with it what we like... but not anymore. We are forced to have our hands tied behind our backs, and watch somebody else do the work for us.

IF you think the electrical 'law' is bad in this country, then don't move to OZ! ........

Anyway i've just scrolled back to the beginning of this thread to see what we were originally talking about!

Hows your car/battery situation?

Wed Feb 16, 2005 7:34 pm

Danstable wrote:The alarm has been OFF the whole time that the second battery has been in.....so I don't see that it can be anything to do with the alarm.

When you say the alarm is 'off', are we talking totally unplugged, or just not armed ?

Most car alarms dont really ever turn off as such, and are always sitting there (using power) waiting for you to arm/disarm etc. On my Clifford, all the sensors are active even when disarmed, it's just that the alarm takes no notice of them until you arm the system. Apart from the extra juice it uses to flash the LED on the dash, the power consumption should not change much between armed/disarmed.

Cheers,

Ian.

Thu Feb 17, 2005 9:45 am

I turned mine off at the siren unit under the bonnet, using the key. Is that off enought.....or is it still likely to be using power?

Thu Feb 17, 2005 2:44 pm

Danstable wrote:I turned mine off at the siren unit under the bonnet, using the key. Is that off enought.....or is it still likely to be using power?

I don't know what system you have, but on my old Clifford Concept 50, the key under the bonnet only turns the siren off. The actual alarm still functions as normal, and the indicators still flash etc.

You would need to find the power wires for the alarm unit, and remove the fuses to kill the power completely. There may be more than one fuse as well. I think mine has a couple.

Cheers,

Ian.

Thu Feb 17, 2005 5:56 pm

Mine is just the standard BMW unit. Have a mulitmeter now so will do some tests at the weekend I recon.

Fri Feb 18, 2005 7:06 pm

Strange as it sounds i had the same problem 6mths ago. It was the electric aerial!!! Diconnect the bugger and see how you go (if you have 1 that is)!!!
With regards to the alarm, iam pretty certain that it will be pulling current regardless of the siren being disconnected. The siren should only pull current in alarm condition.

Guest · Fri Feb 18, 2005 9:18 pm

i have been using my solar charger now for a few days and its starting first time every time now only cost me Ãƒ”šÃ‚£20 well worth it well i think so anyways and a big thanks to Lizzie from here for recomending it to me !!!

Lars