Battery Draining

[FalconXtreme 10+ year member]

So if my car sits for like 3 days the battery will be drained so much it wont start so i have to recharge my redtop. i figure the drain is coming from my stereo system. so what should i check to fix it? when i turn my car off my amps turn off via remote wire. my autotek amp has a bass remote that also has a power led and that turns off with the car so i figure that isn't a problem? where else should i check for a drain?

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[ExS 10+ year member]

Do you listen to music when your car is off?

 

[TeenWolf 10+ year member]

If your stereo is turning off, then the stereo is not your problem.

How old is the battery? Is it possible that the battery just can't keep a charge?

Try disconnecting the system for a few days to see if the battery still drains. I bet it will.

 

[stones 10+ year member]

A bad relay will cause a current drain, one thing to consider.

 

[FalconXtreme 10+ year member]

what type of relay? this is a fairly new optima redtop i just had it exchanged earlier this summer because i thought it was the battery. i'm going to try the disconnect the stereo and see if it still drains trick but keep the tips comming

 

[iceteebone 5,000+ posts]

are you running a second battery?

 

[FalconXtreme 10+ year member]

thats a negative. one red top and a 200a iraggi alt

 

[stones 10+ year member]

what type of relay? this is a fairly new optima redtop i just had it exchanged earlier this summer because i thought it was the battery. i'm going to try the disconnect the stereo and see if it still drains trick but keep the tips comming

They are little black boxes under your hood, I had one that controlled the daytime running lights and the voltage regulator on the alternator fail in the closed position so the voltage regulator and daytime running lights had power all the time, I simply replaced the relay with a new one and the problem went away.

 

[FalconXtreme 10+ year member]

so these relays are seperate from the fuses under the hood? or is that what your talking about?

 

[stones 10+ year member]

Ya, relays and fuses are seperate they are little black cubes that turn shit on and off with the ignition, if one gets stuck in the on position you will have a battery drain.

They look like this

One way to test for a current drain is to take a simple tailight bulb and solder a couple wires on it for the + and -.

Remove your positive battery terminal and connect the positive wire for the bulb to the battery then connect the negative wire to the loose battery cable.

Now with the car off it shouldn't drain enough current to make the bulb glow, but if the bulb glows brightly somthing is definitely on when it shouldnt be.

This works because when everything is off there should be no negative path for the bulb to work, but if a component is running there is a negative path so current is pulled through the bulb, the brighter the bulb shines the greater the current draw.

 

[FalconXtreme 10+ year member]

so ur saying connect the positive lead of the bulb to the positive battery terminal and then connect the negative lead to the positive battery cable that i took off the terminal? also how do i check if a relay is blown?i drove my car on thursday and it had a 1/3 battery charge on it. so i'm going to check 2morrow to see if it is dead or not/

 

[stones 10+ year member]

You make it so any current coming from the battery needs to go through the bulb before it gets to the electrical system, the brightness of the bulb is an indicator of how much current is being drawn.

To see if a relay is stuck in the on postion you hook up the bulb and assuming it is glowing and showing a current draw you get a buddy to start disconnecting relays, if you disconnect a relay and the bulb suddenly dims or goes out in responce then you have found a relay that is on when it should not be.

If no relays are found to be defective move on to the stereo components, pull the fuse to the amp to cut power to it, pull the fuse for the radio .... basically you start dissconnecting things untill the bulb goes out, the thing that make the bulb go out when you dissconnect it is the offending component.

As for polarity, positive to the positive battery terminal negative to the positive battery cable.

 

[Justshoe 10+ year member]

Actually stones its better to do that on the ground side. Get a test light and go from batt post - to the cable - take off cable and put a test light between them. Depending on the vehicle and how many computers it has it may take up to 45 mins for them to shut down like this. So what you would need to do is get a jumper wire because the testlight is not a large enough load and put the jumper wire on the same path the test light is for about a min or 2 to let the computers and such time out. THen if you still have a drain and the light is still illuminated start pulling relays and fuses till it goes out then you know which circuit your dealing with to try and isolate a problem. Im a dodge tech and we generally find it to get a map light or hood/trunk light staying on due to a faulty switch. O yea make sure all your doors and closed and you may need to disconnect the hood light if u have one otherwise it will pick up the drain right away.

 

[stones 10+ year member]

Sorry, I always think in terms of the older cars, before they had all that cursed computer crap. God I miss the old days, and my 86 cutlass brougham //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif I saw a cutlass that looked exactly like her the other day, same rims color, trim level, I swear I got a stiffy just looking at it.

Anyways, I wasn't sure if using the + or the - battery terminal made a difference, thanks for clearing that up.