Boy do I need the Brain Trust about now... Wrench question

[LWJ]

Gents, (and occasional Gals)

Here is what I have:

My newly adopted daughter (23) and slightly disabled, has a 2014 TDI Beetle. It was her dads. He died. I got the child. She got the car.

Things were moving along pretty well until she called in a panic that her car, which she drives daily, had died. Well, it had a dead battery (11.x V). I charged it over a day and the car ran fine. It put out 14.5-14.12 V on idle. But we noticed that the battery voltage kept on decreasing over a few days. Until it ended up in my driveway DOA. I gave her my wife's car (wife not happy), charged the battery, and took it to a competent indy wrench.

They could find nothing except one of the key fobs was bad.

I took it to a WV dealership and had the same result. Odd, I think.

I swapped out to a good key fob and left it in my driveway for a day. A smart neighbor suggested a load test on the battery. I did this. It went from 12.5 or 12.5 to 12.2 with 2 minutes of high beams. Aha! Bad battery. Off to Costco. Grabbed a new AGM battery and I am feeling pretty darn smart. New battery measures 12.79 V. I start the car a couple times. Leave it in the driveway and I am ready to collect my wife's car and move on. Except the car didn't cooperate. The next afternoon the car was as dead as they come. 3.6 V. HOLY BATTERY DRAIN BATMAN!!! I charged it up over a day and a half. I drove it yesterday. It drove great. No idiot lights. Nothing weird. I did a 1)load test - Great! 12.5 V and 2) battery drain test with my DMM set to measure the amperage draw. It starts high at 2.++ A and then went to a solid 0.00 A. What??? No draw? I am flummoxed. I charge over night last night to 12.8ish V. I sent my wife out to drive the car and test anything and everything. The one thing that my "daughter" does that we have not done is lock the car. So, I have my wife set the car to replicate exactly the settings that she would leave the car - doors locked after a drive. I set the ammeter to measure and we have been at 0.02 - 0.01 for the last few hours. And, the battery is at 13.01.

As there is zero draw, I have no idea what to do? I can't pull fuses and check circuits as they are not pulling meaningful power. My last grasp of hope is 1) PPOT Brain Trust 2) Having my daughter clean all of the 5hit out of the car as it is a pigsty and I can't see, smell, detect anything through all of her garbage. And 3) last case is I will sell it.

Ideas??? I am really at the end of my options. I did call an electrical specialist. He said if there is not a drain, he can't fix it. And I agree.


Thanks! It is a joy to have a boat-load of smart people to gather ideas from!!!

[LEAKYSEALS951]

Named must your voltage draw be before banish it you can. Patience you must have.

[john70t]

Originally Posted by LWJ

Gents, (and occasional Gals)

They could find nothing except one of the key fobs was bad.

It went from 12.5 or 12.5 to 12.2 with 2 minutes of high beams. Aha! Bad battery. Off to Costco.

The next afternoon the car was as dead as they come. 3.6 V. HOLY BATTERY DRAIN BATMAN!!! I charged it up over a day and a half.

As there is zero draw, I have no idea what to do? !

There should be some 'small' draw for clock/radio/security whatever.
Use a different multimeter and check settings.
Amp flow function might use a different port (protected) than Voltage or Ohms.

Remember there is 'surface charge' and 'deep charge'. uh. I think those are the terms...
Surface is like static electricity and will drain off the surface.
Deep charge capacity is the stuff that turns diesels at -20deg.

~12.6V should be held after running and lights are left on for a few. (ie static charge of 13V+ is removed)
~12.4V is 50%.
~12.2V is about 25% remaining iirc.
Electronics don't work below 12V or 9V depending. again iirc.

I went through something similar. Mom's Pius was left with an interior light on. A borrowed static jumper gizmo made it run for a few seconds and then shut off. No joy. New battery was purchased from local dealership and then that failed. 2V. Which is almost impossible for a new battery under any load. Took it back. They tested it for about 5 hours, gave me a complete federal database search, made me sign over my second born, and finally gave me a replacement battery that works.


edit: there is the very random chance that the key fob is continuously sending signals but I don't think it is possible to drain that much juice.
There would have to be something in the car using it.

[rockfan4]

Does the car have touch unlock, where you touch the door handle with a fob nearby and it unlocks the car? Does it have push button start? It sounds like a module isn't properly going to sleep when the car is shut off and locked. You don't store a key anywhere near the car, do you?

As a former owner of a VW Jetta with weird electrical issues, I'd say trade that sucker or sell it to Carmax or someone that won't hunt you down when the battery dies on them.

[fanaudical]

LWJ - I have VAGCOM / VCDS on a laptop if that's ever useful to you (probably not helpful in this situation).

Seems like you have an intermittent battery drain. My first guess would be the diode bridge in the alternator going out (and that is connected all the time).

I would definitely get the car cleaned out. Look for standing water or liquid in the foot wells and near the door jambs. VW/AUDI love to hide electronics there where they can get wet. Wet electronics may have an intermittent drain. (Had this problem on an 99 A6...)

[sc_rufctr]

Could the replacement (new) battery be faulty?

Simpler things have caught me out in the past.

[LWJ]

Keep em coming!

1 - I don't have a lot of patience!!!
2 - There is a 0.01 - 0.02 draw currently (acceptable) and the battery is 13.0 V
3 - Agreed the new battery could be cheesey. I did a load test. It passed with flying colors.
4 - Yes - push button start!
5 - Yes - there could be something weird in the car. Daughter is a PIG.
6 - I scanned codes with a cheap-o scanner. Nothing. I assume dealer did as well. May very well take Fanaudical up on his offer before I sell the darn thing.
7 - No - the key fob is nowhere near the car.

All great ideas. I don't think these are the issue yet. More please! You all rock!

[pwd72s]

https://www.youtube.com/watch?v=KF1gijj03_0&ab_channel=EricTheCarGuy

Watch above on how to find a parasitic draw...probably something she leaves on...or perhaps a defective switch that leaves something like a trunk or glovebox light on when they are closed.

(edit) Possibly better info: It covers how to find an intermittent draw...which sounds possible with this VW.

https://www.youtube.com/watch?v=6xFo_oHFF48&ab_channel=FordTechMakuloco

[LWJ]

^^^Paul’s video gives me an idea. He mentions if voltage goes low, the modules get wonky and can increase the draw.

Maybe my new battery drew down a touch after I started it? I never fully charged it as it showed 12.7 when new. Hmmmm. Possible, given that the car is being PERFECT with a full charged battery.

Veeery interesting.

[Rusty Heap]

with your ammeter installed inline with battery mains, you say you only see .02 current draw, was that with the ignition key on or off? Turn key on, turn radio on and you should see about 4-5 amp draw. See if meter reads that.

[masraum]

Originally Posted by LWJ

^^^Paul’s video gives me an idea. He mentions if voltage goes low, the modules get wonky and can increase the draw.

Maybe my new battery drew down a touch after I started it? I never fully charged it as it showed 12.7 when new. Hmmmm. Possible, given that the car is being PERFECT with a full charged battery.

Veeery interesting.

12.6 should be fully charged for an automotive battery.

[1990C4S]

Disconnect the battery at night and see if the car runs reliably each day.

I think you have a parasitic draw that you're missing. Or a bad battery. The test above will determine which it is.

[LWJ]

^^^Rusty. It is a push button start. I don’t know if I can turn anything on without pushing start. Example is the windows. The car seems to need to be turned on to simply run the windows up.

And, I don’t even have the basic owner’s manual.

This is a great clue/train of thought.

As to Masraum, I agree on the 12.6 fully charged spec. I was considering a surface charge reading at 12.7 and then having the voltage plummet after- when I ASSUMED that it was good.

Going out to measure now.

Great ideas all! Thanks!

[john70t]

You should get/make a couple test wires with the alligator clip on both ends.
It makes it easier to keep a multimeter hooked up while cycling the key.

[911 Rod]

Originally Posted by LWJ

^^^Rusty. It is a push button start. I don’t know if I can turn anything on without pushing start. Example is the windows. The car seems to need to be turned on to simply run the windows up.

With my wife's Corolla you push the start button twice without your foot on the brake and it turns the car on without starting it.

[pwd72s]

Originally Posted by 1990C4S

Disconnect the battery at night and see if the car runs reliably each day.

I think you have a parasitic draw that you're missing. Or a bad battery. The test above will determine which it is.

Agreed..probably missing an intermittent draw.

[Soterik]

Is there a "spare fob" that is lost in the car? This happened to my dad... and we found a fob that he had lost under the seat, and it was the source of the issue... The fob in the car left the car "energized" all the time and it was also a push to start button car.

[Chocaholic]

Originally Posted by Soterik

Is there a "spare fob" that is lost in the car? This happened to my dad... and we found a fob that he had lost under the seat, and it was the source of the issue... The fob in the car left the car "energized" all the time and it was also a push to start button car.

Sounds like a good excuse to have your daughter de-funk the interior! Even if no fob is found, her gas mileage will improve with many pounds of junk unloaded.

[drew1]

Sometimes ohming between disconeted battery terminals as things are switched on can find a draw but with all of the relays nowadays, not the best. You probably will not see a change in ohms as you turn stuff on because of all of the relays in modern cars.

Neither can amping to check current draw between a battery termial and disconected cable always find it.

Best way I have found is to pull a fuse and check voltage between both of the terminals in fuse box. Battery voltage read and you are on right path. In a 2000 Ranger found a bad radio CD player this way. On 96 Chevy truck found bad warning buzzer this way when was getting slight buzz. Done away with and battery drain quit.

[1990C4S]

If there is active FOB in the car, then the car should start when the known good FOB is miles away...

You have all the symptoms of a significant parasitic draw. You might think about selective fuse removal as a test.