Mazda Rotary Club

Hi all,

Problem: - the battery on my \'96 3rd Gen RX-7 is draining to flat within 2 weeks of non use of the car.

History: - imported from Japan, came with an after market double din stereo.  Had C-West sleek headlight kit installed and an alarm  and tracker installed.  New battery installed.

Last month I didn\'t use the car for 3 weeks.  The battery was flat.  Replaced the battery rather than recharge it.

This month didn\'t use it for 2 weeks, battery was flat.  Recharging it using a trickle charger, it\'s taking a long time, last checked it was approx 37% charged after 26 hours.

Solution: - find out what is excessivley draining the battery.  This is where I need your help.  I have a list of things to check: -

1) The boot light is apparently a common thing left on.  I have never noticed a boot light but I will investigate.
Where is the switch for the boot light?

2) The aftermarket stereo may be using too much power.
Can I shut this off by pulling a fuse?  Which fuse is it?
I\'ve seen the english translated cover but there is no mention of the radio, see this thread.

Can anyone suggest any other possible drain sources?

Thanks in advance for your help.

Chris.

could be an alarm prob too.

you should check the int light  in the car or the boot goes out.

 i had a headlight prob were the pop up was seized and wasnt shuting compleatly so was still doing its thing even though the ignition was off,,

Has the battery you got the right one for the fitment..... I don\'t want to sound condecending..... but it is just that a lot of garages or places that sell batteries tend to give you what they have in stock or what they can get hold of quickly as opposed to what should be in there.... I believe you should be able to easily get a 60 to 70 amp hour one in.

If it is not the battery then how about the alternator.....is it charging the battery corectly when the car is on.... should be reading 13 to 14 volts or there abouts if you put a voltmeter across the terminals with the car on.

Failing that then I guess you have to go on a bit of a fact finding mission to see if there is anything which is draining the battery.

I don\'t think it would be the stereo unless it is left on which I doubt.

Alarm or interior lights are the normal things in most cars that cause this problem.

As for the recharging taking a while - what type of battery is it that you are recharging and what type of charger are you using ?

t2rew : I had a good hunt for this boot light but cannot see it anywhere.  Where should it be?

The alarm manual says it should use 25mA when the alarm is on, which is a very small amount.  I read that the avg. total drain should be about 100-150mA.

Andy T : The battery I have in now is 12V, 50 amp hour.  Would sticking in a bigger amp hour just mean it wouldn\'t drain as quick (a good solution!)?  If only batteries were cheaper!

The battery is fine when the car is used.

The charger is a trickle charger bought from the TVR online store :eek:

After 50 hours the battery is finally as good as fully charged.

I have unplugged the CD changer which I doubt would drain much at all.  Anything else will require more work fiddling with the fuse box.

Can anyone tell me which fuse the stereo uses?

my battery drained really quick after i fitted my head unit, i think it was cos i hooked it up to a dodgy earth lead

Keeping this thread alive in the hope someone can answer these questions: -

Where is the boot light situated, specifically?  Is there a manual override switch for it?

Can anyone tell me which fuse the stereo uses?

The boot light is fixed onto the rear hatch. Open it up and you will see it clearly.

On this light is an on / off switch. I had a battery drain problem last year where I kind of half closed the rear hatch and the light stayed on, so I now leave it turned off all the time.

Regards

Max

Sorry, I am not sure where you mean, rear hatch?  Could you be more specific for my sake :)

I had a really good look in the boot last night and couldn\'t see anything :(  Can\'t see the wood for the trees....

Thanks.

it should be actually on the tailgate itself ... ie. the bit that opens

Sorry to be a pain, but I\'m after the exact location...

On the bit that opens is good, but where abouts?

The hinge end, opening end? On one of the sides? In the centre..?

Is the boot light _always_ included with every model?

Thanks.

Chris :

The reason I asked about what type of battery it is and what type of charger, is that if the battery is a calcium type then these tend to be much harder to recharge if they go flat, hence why it might take a lot longer using a normal battery charger.

With regards to the battery capacity, any battery will eventually drain if left without usage over a period of time. Even if a car has no fault on it. But if it is a larger capacity (or better) battery then it might last longer inbetween the need to run the vehicle (or charge the battery).

Is there anyway of measuring the total drain using a simple multimeter ?

Andy T : not sure on the type, but the charger handles all common types of battery.

I  can measure the drain, but it is a bit of a hassle.  Need to disconnect battery, place multimeter between the disconnection and that will tell me.  Planning to do this on Sat.  Not sure if I can have the alarm engaged whilst measuring though as disconnecting the battery will set the alarm off.  I\'ll soon see :(

Hi Chris

You probably have had this answered but the stereo fuse is in the fuse compartment under the drivers dash, (between the bonnet pull and the accelerator pedal)

I can\'t remember which fuse it was, I changed it the other week, i got the diagram from doing a search on this site, but i found it not to match my fyse box, ( I just pulled one out till I found it was broken though that won\'t work in your case

do a search on fuse diagram, if not I can dig it out for you

Cheers

Dave

Could be the stereo. My 323 had a ford radio fitted, and battery would only last about 3 days without driving. Replaced it with Pioneer, and its now fine.

I would suspect the alarm first, though - they are all cr4p!  You might have to find a way to override it? Then see what happens.

I read somewhere you can disconnect the battery, then watch for a small spark every time you reconnect it, remove fuses one by one as you repeat this, until there is no more spark. Then you\'ll at least be in the right area.

The boot light was dropped, either in 1996, or in 1994.

davefrith : Yep I have a Jap translated fuse cover diagram, I\'ve heard it may not be accurate for everyone though.  I\'ll turn the radio on and start pulling fuses till it stops!

GaryS : Interesting, I\'m not just being a blind fool then :p  Mine is a \'96.

I\'ll post my findings - here\'s hoping I find something!

Thanks all.

Martiny....

The thing about sparking... normally happens with most cars when you connect a battery and depends on which way round you connect i.e. pos first or neg first ?....

I cannot test the battery drain because this involves disconnecting it and completing the circuit with the multimeter.  When I do this, the alarm goes off :(  Must think it\'s bing hot-wired or something :confused:

I found a fuse under the bonnet close to the battery marked "stereo".  Too easy I thought, pulling it didn\'t stop the radio blaring :(

So into the driver footwell I clambered after removing my scuff plate and the panel that hinders access to the fuse box.  My first guess was to pull the "cigar" (:D) fuse.  Hey presto, this killed the stereo :)

Now it\'s a case of leaving the car and seeing if the battery drains as quick as before.  It certainly seemed to be charging quicker, but this might be because the battery was not as flat as before.

Until the next findings post...

Thanks all.