Help - Car sucking life out of my batteries!

[24Ozed]

Hi Guys,

I'm new to this forum, i'll do the whole intro thing after i get some good pics etc!.

But right now I'm Having a small problem with my brothers zed that would like some help / advice on.

 

Its a 260z 2+2, fitted with RB20det (actually for sale in classifieds section)... yeh i know this isn't the best way to advertise with a "Help" in the subject on a tech section...

 

Ok... now to the problem....

 

The car seems to be draining the battery, I had the battery on charge for a few days.. chucked it in and within a couple of days and a couple of drives the battery its reduced to nothing.

 

One thing i have noticed which seems strange to me is that the Volt Meter gauge on the dash is always reading fairly high (even when ignition is off)..

 

Correct me if i'm wrong, but i thought this would only show a reading when the key is in "Accessories" or "on" position ?

 

I have the feeling something is drawing from the battery constantly...

 

Firstly is this normal for the voltmeter gauge to read whilst ignition in "off" position.

Secondly, Whats the easiest way to find out what is sucking the life out of my battery.

 

I've tried a couple of different batteries with same result..

 

Obviosly i need to sort this before i sell, I thought it'd be best to ask you guru's on here before i hand over my hard earned cash to the auto electrician.!

 

Any help would be GRAND!.

 

Travis

[Zedman240®]

I remember the 260's voltmeter is always "on". So even when the ignition is off, battery voltage is always displayed. Do you have an alarm fitted? They sometimes remain in a mode that sucks alot of battery power. Try hooking up a multimeter to measure current at the battery with the ground lead off and measure the current draining the battery. Its ok to have some small current there but nothing to serious. No interior lights staying on? cd player? Just guessing...

[24Ozed]

Thanks Zedman thanks for your response, yes has an alarm fitted.

Will check it out over the weekend.

 

Can you give me some idea of what readings i should expect with ignition off... and also what sort of reading when engine running at idle?

 

Thanks again

Trav

[sco_aus]

There is a cheap and easy way to fix it as I had the same problem with my RB, install a battery isolator switch.  All you do is remove it when you leave the car and it doubles as an immobiliser.  Obviously if you can find the fault then fix it, but if you get stumped like me, this is the way to go.

[Zedman240®]

With ignition off, usually theres less than 400ma. Unless you have a clamp meter to measure current (Clamp meters just go around the cable rather than "breaking" into the circuit ie removing cables and can measure higher current etc) normal meters only go to about 10 amps. Charging rates are sometimes higher than that and may damage the meter. If you know someone with a clamp type multimeter, might be better if you let an autoelec try and solve it. When a car is starting, expect around 240 amps, more if your starter is worn! Member Mayhem on here could give some pointers...? Without having the car in front of you, its hard to diagnose.

[24Ozed]

Thanks again Zedman!.

I'll have a look into this on the weekend.

Will update the post with the source once found.

 

sco_aus  - Wouldn't be much good for me since i've got central locking / alarm. Would render these useless!. I guess at least i've have some charge in my battery to start it! Thats a plus!.

 

Cheers guys

Travis

[sco_aus]

Yeah thats a good point, i guess ya turn to extremes when everything else fails hey, lol

though if it turns out to be the computer sapping the power then a switch to turn the power off to the computer would still keep central and alarm working and lower insurance costs being a form of immobiliser.

[RBZ 260]

do what the guys said at the top. get a multimeter.

 

10A range set the probes in the correct slots. dont try to turn the engine ovre or the fuse in the multimeter will blow. no need to start it anyway.its the off possition current u interested in.

 

unplug the battery terminal and place the multimeter between the battery and the power cable or body ground doesnt make any diff which one you do.

 

read what it shows on the meter. 400mA is way exessive and will flat you battery in no time. should be around 50ma or less.

 

if using more than that start pulling fuses and or disabling things. ie central locking and alarm, radio etc..

 

the currrent should drop when u get the coulprit. you could try this on another car that doesnt chew battery and as a refrence check how much current does it draw when all off.

 

closer to 0 is best. alarms shouldnt chew more than 25mA some better ones do even less when armed with all sensors are monitoring.

 

the flashing led may run at 10mA but it runs for a very short time. So if u see the numbers jumping when its armed it shouldn't jump more than this.

[warrenz]

I experienced the same problem once and it turned out to be the glove box light. I was not turning off when the lid was closed. Adjusting the lid hinge fixed that.

 

Warren

[Enzo]

Hi,

  I had a similar problem in another car recently. The regulator in the alternator was burnt out allowing the battery to discharge even when the key was turned off. A new alternator had to be fitted. Take you car to an auto sparky for a checkup.

David.

[OZ001]

try this it solved my problem

 

p.s u can use other ones too i just bought these cause they look pretty

 

 

 

HKS Universal Circle Earth System

 

Circular Grounding System

 

By utilizing a 24-karat gold-plated distribution block and multiple grounding points, improved idle and drivability are often obtained as the additional grounding points equalize resistance and voltage between various ground points. Each 8-guage spiral twined cable is wrapped with signature HKS purple plastic to protect and add color to the Circle Earth System. Vehicle-specific kits include pre-measured cable lengths and distribution blocks. The HKS circle plate allows for the freedom to choose the thickness and the number of wires (up to 24 lines) to be used. Depending on the specific application, either the Separate Type (remotely located from battery terminal) or the Direct Type (directly mounted onto the battery terminal) is utilized.

 

24K-gold plating and high quality wire - Each of the eight SCQ wires consists of 658 winded 0.12mm lines that allow each wire to withstand up to a maximum of 65A.

 

 

hope that helps your problem

[xa1973]

 

 

 

Another thought to add

 

 

If you have an after market sound system installed ( with or with out amp ) these systems usually have a huge power feed lead with Fusable Link ( with a light of some description in it ) that are connected directly to the battery and draw current 24/7, these will destroy a good battery in no time particlarly in older cars that do not have as many electronic power management controls, relays etc, you may have an open relay drawing current somewhere in the circuit

 

Check your engine inspection light, courtesy lights for leakage, is your battery charging, do you have good earth to body or chassis, in older cars I usually run my neg lead to an engine mount

 

Cheers

 

[Mr240z]

4 Months late, Pretty sure he has sold the car by now.

[xa1973]

4 Months late, Pretty sure he has sold the car by now.

 

 

LOL

 

YOUR RIGHT!!!!

 

That will teach me to wear my glasses

 

 

Cheers

 

[dazzed]

some alarm systems have a back up battery in the siren, over time the battery deteriorates  and requires the car battery to keep it charged,