Battery Drain on a G60

[Alexander 0]

Hi all,

 

I realise this is quite a common problem but I'm looking for some more specific pointers how to diagnose it.

 

My 91 G60 will drain it's battery totally flat (dead dashboard, etc) in 5 days. Obviously this is annoying! It's got an uprated headlight loom, and a Toad AI606 alarm. It also seems to have the remnants of another old alarm in it, and while I did remove a CD changer from the boot when I got the car, the radio is a pretty standard old Alpine CD unit.

 

I've measured the voltage on the battery, and it stays at 12.10v - 12.15v even when I pull fuses one at a time, but I get the feeling I need to be checking something else? Not very canny with electrics etc to be honest so any advice would be gratefully recieved!

 

Cheers!

[nmahi 0]

i got a drain at the moment with mine, turn out to be the alternator....try check the voltage with the car running, see it drops.....if the volts go up then alternator is ok.

 

my dropped so the car was basically running on battery power and not charging on load plus lights, ICE etc....hence it dying within 2days use!.

 

see how u get on.

 

bob

[big ben 10]

i have read about dodgy relays on the headlight loom running the battery down... worth a look??

[Alexander 0]

Thanks guys, will check alternator tomorrow.

 

How would I be able to test if a relay is dodgy in the headlight loom?

[big ben 10]

maybe take the loom out and put the original loom in and see if it works, if the battery doesnt go flat anymore its the relay

[dr_mat 0]

If the battery is only reading 12.1 volts it's only 50% charged..

[Alexander 0]

Not really confident enough to remove the loom on spec, and I don't have the original.

 

I'm not surprised it's only half charged, as it discharges constantly!

[nmahi 0]

have you got central locking of the alarm fob? .....if so try this, arm the alarm and then listen near the boot of the car if the pump is still going.......ive recently started to notice this with my car. i think it might be a faulty door pump.

[Alexander 0]

Ah nice one nmahi, I'll try that. Alternator seems fine, as the voltage goes up when the car is running.

 

I think (after talking to my dad) that I need to put the meter in series with the battery with the car off to be able to measure the current being drawn. I'll do this as soon as it stops bloody raining!

[nmahi 0]

i know how frustrating it gets, i got disconnect my sub, pull out my stereo, then check all fuses, then pulled them out one at a time whilst check power drain, the pulled the central locking system apart, then my pass elec window stop working, so had the door panel off.......then check all the switches and heat panel (converted to LED's), then took it to the alarm place to check that....turns out the alternators not charging, hence the back up battery in the alarm dying causing the central locking to play up.

 

If had the alternator refurbed, but aint put it back together yet "rain", im just happy i got another car to drive around at the moment.

 

:brickwall: :brickwall: :brickwall: :brickwall:

 

bob

[Alexander 0]

Hmm ok that was pretty inconclusive.

 

I put the meter in series with the system - disconnected the + connector of the battery and connected it to the - of the meter, and connected the + of the meter to the + battery terminal. On the 200u Amp setting of the multimeter it showed a reading of 00.1, fluctuating to 00.2 occasionally. I have no idea what this means?

[dr_mat 0]

I put the meter in series with the system - disconnected the + connector of the battery and connected it to the - of the meter, and connected the + of the meter to the + battery terminal. On the 200u Amp setting of the multimeter it showed a reading of 00.1, fluctuating to 00.2 occasionally. I have no idea what this means?

 

Sure it was "200u amp" and not "200m amp"? If you're drawing 0.2 uAmp (0.0000002 A) the battery will last approx 36,000 years before going flat... I suspect it wasn't properly connected, myself .. ;)

 

FWIW to drain the battery from half charged to "can't start the car" in five days you're probably looking at around 0.2 Amps, or 200 mA or 200,000 uAmp.

[Alexander 0]

Hmm I think the main problem here is that I obviously don't know how to use a multimeter!

 

I'm stumped, I think I'd better just bite the bullet and get a professional auto electrician on the job. :(

[dr_mat 0]

I'm stumped, I think I'd better just bite the bullet and get a professional auto electrician on the job. :(

 

You had the right idea - putting it in series with the battery, but something went a little awry .. It's hard to put it into series because you have to somehow add it to the circuit but NEVER break the circuit at the same time.

The only way I ever figured to do that was to put the meter in 10A mode (usually you have to switch sockets for one of the probes), touch one probe on the centre of the battery pillar, with the clamp still attached but only loosely, then touch the other probe to the clamp and gently lift the clamp so it loses contact with the battery pillar - that way all the current is going through the meter and the car never dropped power (circuits behave differently when you apply power compared to when they have been running for a while).

 

Of course you need seven hands to do this..

[dirtytorque 0]

you have not said what the voltage is at the battery when the car is running???

 

Is the alternator charging the battery?

What is the battery terminal voltage when the car is idling?

[dr_mat 0]

Yeah that's easier.. Should read 13.8 - 14.2 volts when the engine is running. It will drop a little if you switch too much electricals on.

[Alexander 0]

Still working on this...

 

What are the main culprits for battery drain? The only bits of the car that don't work as they should (leading on from previous posters central locking woes etc) are:

 

* Rear heated screen doesn't work

* One of the heated wingmirrors doesn't work

 

The car used to have a boot install, which I removed, but there's still a thick power cable going from the battery to the boot - I'm going to disconnect this. Would a positive cable touching the bodywork cause the battery to drain?

 

If anyone can give me some examples of possible causes, I can try them one by one in a trial and error stylee.

[borarob 0]

i had the same problem with my C - in the end it turned out to be the radio draining the battery. Just so happens my radio is also an Alpine...

 

does your radio turn on with your ignition / only work with ignition on or doe it work all the time? If it works all the time chances are it is wired with the permanent and switched inputs on it both wired to constant 12V - if this is the case then your radio is never actually turning off properly and is always essentially in standby mode - this was drawing enough current to drain the battery in 4 days.

 

if this is the case you need to wire up your radio 'properly' i.e. give it the separate constant and switched 12v it wants. This will stop it from working if no ignition on but will also mean it is properly off when you turn the car off. Once i did this everything has been fine, have the left the car for over a week and no issues what so ever.

 

I'd also give your batt a proper charge with a mains trickle charger

[Alexander 0]

Right. That's awesome - the radio DOES work with the ignition off, so this definitely sounds like a potential culprit!!! I'll try disconnecting it in the first instance and see if that gives the battery extra life. Thanks very much!

[nmahi 0]

Right. That's awesome - the radio DOES work with the ignition off, so this definitely sounds like a potential culprit!!! I'll try disconnecting it in the first instance and see if that gives the battery extra life. Thanks very much!

 

still having problems mate?......

[Alexander 0]

One thing I just thought of regarding the radio - every time I disconnect the battery, I lose all my settings, so if I change it to use the switched 12v, won't I lose all my settings every time I turn the engine off? I would assume the radio's supposed to have some kind of battery backup? Maybe it's run out... I will RTFM.

[borarob 0]

no you won't keep loosing your settings.

 

as i said the radio has 2 power inputs, 1 switched 12v from the ignition and 1 constant 12v from the battery. the constant feed keeps your memory settings, the switched 12v turns the radio on.

 

i don't think rados have a switched ignition feed lurking behind the head unit as standard - i certainly couldn't find one. Easiest place to take one from will be the courtesy light in the glovebox.

 

your alpine will have info / diag on it telling you what the wires are, red is usually perm and yellow switched

 

almost 100% sure this will be the cause of your issue and all will be fine if you get it wired up right

[Alexander 0]

Thanks mate, I'm looking at the wiring diagram now for the Alpine. Not had chance this weekend to pull the radio out, but I will if the problem persists.

 

Last week I disconnected a thick positive cable from the battery - it goes to the boot and used to power an install there once upon a time, it's got an inline fuse as well. Today I started the car up after it being sat for 3 days and it jumped into life - normally it's a bit sluggish to start after that amount of time idle. Don't want to count my chickens but it's a positive step!

[Alexander 0]

SOLVED !!!

 

Pretty simple actually - there was a big thick power wire going from the positive terminal all the way to the boot, where there used to be an install. This had an inline fuse that happened to be sat in a pool of mayo that had come from the rocker cover breather hose. I guess it must have had that leak into it over time and made a circuit. Anyway, I disconnected this extra wire from the battery and the car is now absolutely fine!!

 

So what have I learned? Always check the obvious things first! Thanks a lot to everyone who helped in this thread! :)

[nmahi 0]

:D