Failure To Start

[KillNThrill24]

Like my cliche title? Good.

This random battery drain of mine is getting ridonkulous. I've got it charging overnight tonight (6 more hours till I wake up anyways) on a 2 amp trickle charge HOPING I can start it and drive it.

The quick rundown:
Car will randomly just be dead. Simple as that. The battery is about a year old I think. And last weekend I parked it Friday night when I got home from work (12:30am), sat all day Saturday, went to unlock it Sunday at 3pm and it was dead as a doornail. It did rain, and I've heard some whacko stuff about rain causing dead a dead battery but I don't know. Where do I start? I have a voltmeter in the back seat so I know I'm going to have to start checking things but I've never really done it before. Electrical diagnostics is not my strong suit. I can run a wire harness no problem, but diagnosing a drain somewhere, or a short, is just something I really hate doing. Any leads on where to start? Car has hid's and an aftermarket head unit if that matters at all

 

[KillNThrill24]

BTW is leaving the battery on the charger overnight a bad idea? It's on the 2amp setting sooo.... Theoretically it should be fine based off how long it takes to charge a dead battery on 2amps. Right?

 

[kb1982]

Check out this vid. It will give you a good idea how to go about it. Unless you have high quality multimeter, dont leave it continously hooked up while you check the various fuses. My el cheapo model is rated for 10 amps for 15 seconds every ten minutes lol. Be sure to have a good charge on the battery also before you go testing it, and also your 2 amp charger wont hurt anything. 2 amps isnt enough to "cook a battery" or make it start boiling the electrolytes.
[video=youtube;VcRG-XBzk7U]http://www.youtube.com/watch?v=VcRG-XBzk7U[/video]

 

[ttocs]

if you have the mach amps in the car try disconnecting them and see if it stops happening. Otherwise that vid shows how to diagnose the problem. Hook up the amp meter and start pulling fuses and when you find the one with the power draw it will be obvious on the meter when you pull the fuse.

 

[KillNThrill24]

Good deal thanks for the heads up and video fellas. I'm hoping it will be something simple. And yeah I have the mach amp(s?). I have the 460 so if it has a high and low amp, which I believe it does, then yes I have amps with an S lol. It'll probably end up dead in the morning, I just ran the hell out of it tonight

 

[ttocs]

you can test if its the amps by disconnecting the hrns that goes to it when you park it and I bet in the morning its ok. They have been more bad then good lately. Sad to say really as it was a nice premium stereo for the time and not many other stereos last 20 yrs today but their time has passed.

 

[KillNThrill24]

So you're saying that my 14yr old amps are causing a power drain? Dammit! Actually no in all seriousness... How does that occur? I mean it requires a hot lead and a remote lead IIRC right? So that means the hot lead is always going to it, but it doesn't get power unless the remote lead tells it to... Shit I don't remember this stuff very well. I'm just curious how the amp could all of a sudden be draining my battery. Well not all of a sudden I've had a drain since I bought it lol, it's just getting bad now

 

[RichV]

Your aftermarket head unit install can be leaving the amps on. Seen that be a battery killer. I would suspect anything electrical that's not OEM 1st.

 

[Burninriverdiver]

Yea the aftermarket head unit paired with amps can cause a drain if the remote wire is hooked up to the constant power wire. I've seen this done a few times. Make sure your remote wire (wire that causes amps to shut off when ignition is not on) is wired separately from the constant supply

 

[uncltrvlnmatt]

IMO start simple. Test your battery, I don't care if it is a year old. I have seen new batteries fail. Check your alternator output, make sure you have 13.5 volts minimum. But it should be higher. If you can check the amp output of the alternator check that as well. Check your grounds on the battery and on the block. The main ground on the block is on the left side at the motor mount. Once you are sure all those things are good, then move on to what these guys are suggesting.

 

[KillNThrill24]

I too have seen battery's fail under a year so I'm not ruling that out, just stating it's only a year old. Infact my old battery froze solid after about a year. But definitely will check the grounds, and power outputs on the battery and amp

I'm definitely curious about the head unit too so I'll double check all my wiring on that too. AS of right now it's started up every time, which is odd.

 

[RICE ETR]

Your battery is roughly 50ah so if it's completely discharged it will take approx 25-30hrs at a 2ah charge. Can you verify it has been fully charged prior to no start? Or is it just charging over night and you try it the next day? Do you have a volt meter? With the vehicle off put the volt meter on the battery to see of there is an abnormal parasitic drain, normal is 175-215mah anything higher would indicate you have a draw somewhere. To add to your frozen battery being less than a year old, that is due to having a discharged battery being left in the cold which to me, suggests you have an underlying issue as this is a reoccurring problem. When a battery is discharged there is only water left as the electrolyte is within the plate, as you all know water will freeze in below 32 and cause damage to the battery. FYI I manage an industrial battery shop.