Can a sub drain the battery?

[stolly]

-Installed a JL Audio sub (10") a few months ago, since the day I installed it I haven't driven the car. Went to start the car yesterday and it was flat as a tack. I've previously left the car for similar periods of time and never had a problem. Just wondering if I've done something wrong? The amp is an audison not sure which model, it had outputs for a sub - simply marked + and - . Obviously I ran cable from these to the red and back terminals on the sub. Cable is fairly heavy, not sure what gauge etc, but thick enough that you could only just fit it into the terminals on the sub. Any clues?

Thankyou

[LBR33]

Hows the water lvl in your battery i highly doubt that a sub turned off would drain it.

[Sumo]

does your head unit supply your amp? Just check to make sure your amp isn't staying on...

[stolly]

-Yeah, battery level is fine and amp is turning off with ignition. I pulled everything apart yesterday and hooked it all back up again, see what happens this time.

[someonestolecc]

It might be just normal anyway and your battery getting tired.

Easy well to tell is pull off the positive from your battery and connect it back up. If it sparks while you do then something is using it up.

[stolly]

It might be just normal anyway and your battery getting tired.

Easy well to tell is pull off the positive from your battery and connect it back up. If it sparks while you do then something is using it up.

-Thanks for that, will give it a try tonight

[Sumo]

Try not to do that, put a ammeter across it... Spikes are painful, and I have seen them blow up a regulator on an altenator.

Sparks are how the bush mechanics go about things....

Cheers

Sumo

[lordsnipe]

could be an alarm or something if you have one installed?

[someonestolecc]

Try not to do that, put a ammeter across it... Spikes are painful, and I have seen them blow up a regulator on an altenator.

Sparks are how the bush mechanics go about things....

Cheers

Sumo

I won't argue about the bush mechanics - however I've never seen it blow anything up though and it happens to me everytime I re-plug my battery up so I didn't think it could blow anything up. I'd actually be interested to hear bout the theory of how it would (not doubting you, just wondering).

Multimeter is the preferred method but not everyone has em.

The alarm could be it but alarms usually tend to draw very, very little

[eXc]

How long was it since you started it last? I know you said you have left it a similar time period before, however you should start (and drive...not just let it idle) your car ATLEAST once a week. If you have a bigger/smaller battery than standard you may need to do it more or less often.

I have had a battery last 6 months off a car, and still crank the car, but the same battery 2 weeks later (also been off the car) was dead as. They don't seem to be a sure thing.

The amp would only effect it if either 1) it was faulty or 2) you wired it wrong, but since you say it turns off with ignition, 2 is not the case. So that leaves the amp is faulty, or the battery is..or there is something else in your system that is draining it.

Grab a mulit meter and see if there is any power on the remote lead, at the amp, while the car is off.

[Godzil_R]

might be your alternator is not working probably so therefore not charging your battery enought

[Sumo]

I have seen blokes checking for drains by pulling fuses and running the lead across the battery terminal. What turned out to be a faulty boot light switch also resulted in his Bosch RE60 regulator giving up the ghost. Coincidental, possibly - but there must be a reason the NSW government puts it in the auto electrical sylibus. We have not gone into ECU's yet (still in 2nd year). But a good way to set off airbags is too give them a nice spike. They also should be able to go off 15 seconds later after the power source is removed (by law - safety feature).

[Sumo]

CC also i forgot to mention, if you have a faulty cell in a lead acid battery that is bubbling.... Leave it too your imagination on the resulting explosion - I have seen what batteries do when they explode, although it has never happend to me - but my boss copped one (disconnecting a battery charger). He got drug out and layed under the tap for 15 mins then they took him to the docs.

Cheers

Sumo

[eXc]

I have seen blokes checking for drains by pulling fuses and running the lead across the battery terminal.

Did you just suggest he short circuits the battery? You couldn't mean that...but I don't know what else you could mean?

[Sumo]

exc: of course I didn't, provided their is a load when you undo a terminal their will be a spark produced. They use the spark as an indication that the load is still present.

Cheers

Sumo