Every few days battery drains out when my car sits

Hello,

It sounds like you have excessive parasitic draw (current drain) in the electoral system that drains the battery.
All electrical circuit with a battery, will have some amount of parasitic draw however it can become excessive due to a faulty electoral component. It could be as simple a the glove box light staying on or could be a shorted out power seat switch.

A normal vehicle electrical system will draw from five to thirty-five milliamperes (0.005 to 0.035 ampere) with the ignition switch in the Off position.

Have a look at this video, it covers on how to find the parasitic draw using a multimeter:

https://youtu.be/z5F7WpgjaRs

https://www.2carpros.com/articles/car-battery-dead-overnight

Please let me know of any questions.
Thank you.

We need to start with the basics. That means we need to run through and make sure any of these items are not remaining on.

Here is a video that will take you through this:

https://youtu.be/z5F7WpgjaRs

The next thing if these all check out is to check what is called the parasitic draw of the battery. We do this by removing the negative battery cable and connect the meter inline. So you connect the red lead to the battery cable and then the black lead to the negative battery post but do not touch the cable to the post. We need the connection to go through the meter so that we can read the amperage.

Next you need to disconnect the hood ajar switch and flip the door latch so that it thinks the front doors are closed and you can access the interior fuse box with out opening the door and waking the bus up.

Then put your meter on amperage and let us know what the reading is. It should be 35 milliamps or less. If it is then the draw is not there yet. If it is higher then wait 10 minutes and make sure the bus goes to sleep. Then if it is still higher then start removing fuses until it goes away.

Let me know what questions you have with this and we can go from there. Thanks

Sure. Take a look at the picture below. You want to put it on amps and put the leads in the amperage ports.

Here is a guide that will help as well:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please let us know what you find with this.

Okay. I just want to be sure you have the doors closed and the hood lamp unplugged?

If so, then that is a 2.5 amp draw and that is pretty large. So is this at least 10 minutes after the vehicle was just sitting there?

You need to give the communication network time to go to sleep. So once this happens you will see the amperage drop and settle to what the draw is.

If this was all done and you have this large of a draw, you need to start pulling fuses and see when it drops and note what it was and what it drops to when you pull that fuse.

If you need to access the interior fuse panel, then you need to flip the latch of the doors so that the TIPM thinks the door is still closed.

When you open a door, it will wake the bus up and the amperage will spike so we want to flip the latch before you start or you will have to wait another 10 minutes to allow the communication network to go back to sleep.

Let me know if you have other questions. Thanks

Correct. I did say hood lamp because you have a fuse box under the hood so you need it open and that is going to wake up this electrical system if you open it while doing this test and that is going to be misleading.

You can start with any fuse box that you want to because we don't know what is causing this so we just need to start working through all the fuses until we find which one causes the voltage to drop.

This is a vehicle that has a PDC so if you get all through all the fuses and none of them dropped the amperage then we are going to have to start unhooking modules but let's get to that later if needed.

I need to stress that you need to open the doors and hood and flip the latches and then let it sit to allow the system to go back to sleep. If you start doing this before the network is asleep you are going to get incorrect results. So if when you hook this up and have 2.5 amps then give it 10-15 minutes and it should drop when the network goes to sleep.

Then where that settles is what your draw is. Remove fuses at that point until it drops to around 35 milliamps. That will most likely show on your meter as.035 amps.

These are IOD fuses and I don't think they are the issue. Even if they are contributing to it, if that is.32 amps it is still too high. You need to be down around.035 amps.

I am attaching the info below on the IOD system as these are systems that need to keep memory alive so they are going to be drawing amperage with the key off.

Please read through this info and then keep going with removing more fuses. Also, are you waiting about 10 minutes and are all the doors closed or the latches flipped so that they think it is closed?

Yes. That is set up correctly.

Again, due to not knowing what the draw is, we need to just start with one of the fuse boxes. If it were me, I would go with the one inside the car and see what happens.

Thanks

Okay. When it goes up and down that is just something that is pulling a small amount of amps and is normal.

If you have 10 milliamps at this point, then that means the issue is not there.

If you left the battery unhooked and then just connected back up through the meter, then the issue didn't happen. More than likely you need to leave the meter hooked up and turn the key on and then off and allow it to go back to sleep to get the issue to come back.

Think of it like a light switch. If you never turn the switch on, then there is no chance for the light to come on. So, in this case, the module or component that is causing the issue is not causing it because the battery disconnect caused it to shut off and just connecting the battery did not cause it to come back on. So as soon as you operate the vehicle and get this component to turn back on the issue will most likely come back.

However, if it does not then I am pretty confident that you have a module that is causing this and resetting it caused it to start operating properly again. This most likely didn't fix it, but it is acting like a restart of your computer where it fixes it for a while.

The unfortunate thing is there is no way to find this issue and fix it if the draw is gone.

Let us know what happens with this. Thanks