A mazda Rx-8

[CamaroAdam73]

My boss has a 2004 Mazda RX-8 with a mystery battery drain, can't seem to figure it out or even make heads or tails of it, he has tried the trick of putting a lightbulb between battery terminal and wire to see if there is a drain, and nothing. New battery, and it's been checked and checks out.

The only odd thing, is that a little red security light is constantly on, any idea's guys? we're flat out stumped on this, and from a full charge, the battery is dead within a week.

**EDII** Ment to say that the security light flash's, it's not constantly on as in solid light-up, but blinks ocasioanlly. From reading around on forums i think this is supposed to happen.

 

[86MCCL]

A short in the Rice Cooker Option?

 

[MD13ailey]

If he doesnt start it during that whole week its probly the on board computers that r pullin it down. they have constant power going to them, along with the stereo it has to have constant power to retain memory. hope that helps

 

[tc1959]

You have to check for a drain with DVM set to read amps. Unhook the neg cable and attach the meter Leeds to the battery post and the neg cable.
Then wait 3 to 10 minutes for all electronics to power down. You should have less then 150 -200 milliamps.
If you have more then that start pulling fuses to narrow down what circuit is causing the problem.

 

[CamaroAdam73]

Thanks for the help tc, but we still can't seem to find it. This car has an extremely complex electrical system so we're just gonna try again monday.

 

[1evilregal]

when you pull the fuses, are you holding the door jam switch in to cut off the int light? learned that the hard way....

 

[CamaroAdam73]

No we didn't, why evilregal??

 

[megaladon6]

agreed, if the car is fine day to day, but after 1 week of sitting, you most likely need a battery tender.
but a couple of questions: where do you live? if it's cold there that won't help.
have you done an alternator check? or a starter drain check?
i've had issues with my TDi in below freezing conditions, turned out the alt was showing good voltage, but didn't put out enough amps to fully charge the batt on drives under 50mi. new testers won't find it as they go off of straight voltage, you need good amp readings.

 

[1evilregal]

No we didn't, why evilregal??

mainly because the dome light would still be on and pulling a drain, and not dropping voltage across your test light...

 

[CamaroAdam73]

Havn't been on in awhile, thanks for the replys.

Found out what the problem actually was, there's a security feature in the car where if they key is left in the ignition it will draw power, even in the off position.

Yes it is cold up here, western PA I'm from SC, ****ing hate this white sh*t yall get every god damn year. But anyways, my boss pulls the car into the hanger for the winter, and just leaves the key in, well thats what was causing it lol.