Help chasing electrical parasite

So, with all this extra time not driving anywhere lately and a 2003 Jetta just sitting parked, the electrical parasites drained my battery dead within a week or so. I got it all charged back up and began testing today.



When I connect the meter in-line from battery to the (-) post, after 10-15 seconds it reads 400 mA constant. When I disconnect the interior relay on the battery fuse box. there is no current draw.



Using the TSB 27 08 04, moving to the interior fuse box and with the door open, but latch closed (2 clicks) and doors locked by remote, I am reading that FUSE 14 has 2.3mV drop. This is the only interior fuse that shows any voltage reading across the fuses. The TSB matrix diagram I interpret as meaning 327mA current draw. This fuse 14 is interior lights, central locking system. I keep my interior lights switch in the middle "off" setting, and they usually don't come on at all.



My question is, Now What?!? I assume these results mean that some light somewhere is shorting out? Do I just pull them all out one-by-one until the V drop goes away? Better plan or way to run this troubleshoot? Any comments or links are appreciated. Thanks in advance. Plenty of time to finally figure this out over here...

I would check as much connects and wires on that circuit. Just pulling bulbs won't find a short, but it will find any that are turned on w/burned out bulb, which you may have already ruled out.

Are you having issues with switches in your door locks?

Every now and then I'd see one of my map lights barely lit, sometimes I would have to start the car and shut it back down to cure it, cycling the key didn't do anything usually.

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Yes, I would think Central Locking is a likely suspect. IDK enough about it, but if you can disconnect any of that, might give a clue.

Glovebox light was off when i opened it. I also worked on the glovebox not long ago. Disconnected the light after taking box out and the V drop went away. Battery (-) terminal in-line detection with 10A setting shows 10mA after 10-15 seconds. Thanks, guys.



New question though. I don't detect any voltage in the connector to the glovebox light, car locked or not?! Is the connector shorted then? Can you buy new ones if I cut this one off to test the wires directly? I tried sticking the voltmeter in the back of the connector where you can see some metal on the wires as they go in the plastic, but no 12v detection? its like it died further upstream or something?


EDIT: There is weird locking behavior. I was just sitting there and car seemed twice to just lock on its own. Keys were in my pocket, but I don't think I pushed it accidentally.
EDIT 2: Yeah, car is just locking itself after 15-30 seconds now. Hmmmm.... now what? Is this a CPU reset of a feature from being dead battery long time?
EDIT 3: It is exactly 30 seconds after unlocking, the car locks itself.

Are you opening the door before it locks back? That is a safety feature if the door isn't opened. My old Beetle would do the same thing with or without opening the door. The computer doesn't see that the driver's door has been opened. If I opened the passenger door everything would play nicely. Check that the door switch is reading that the door is opening. I think you can check that with VagCom. My wife's vert had a issue like that but couldn't find the problem even after changing the door lock unit. It wasn't until the window motor went out in the passenger door and found water intrusion in the computer card in the door motor. New motor and everything started working like magic.

If the computer/module doesn't detect that you've opened the door, it will automatically lock it, I guess as a theft deterrent. This is usually a bad switch in the door module (look up the $3 door fix). However, since you also have a drain, it may be something else wrong with the module or wiring. Alternatively, you have 2 problems.

EDIT 3: It is exactly 30 seconds after unlocking, the car locks itself.

That's normal, unless you open a door before the 30 is up.

You'll save yourself a ton of effort if you track down the official VW Technical Service Bulletin in my sig and narrow down the parasitic drain step-by-step with your multimeter.

The "ammeter in series with the battery" method is challenged at best on CANBUS cars with sleeping convenience modules.

EDIT: missed the middle where you were using the TSB... good on ya!

Turning the ignition on and off will also prevent the re-lock.

If the driver door switch that indicates open is bad that's what causes the re-lock.

Another take on the TSB:

https://youtu.be/lRcj1fQcWwU


EDIT: missed the middle where you were using the TSB... good on ya!

wonneber said:

Turning the ignition on and off will also prevent the re-lock.

If the driver door switch that indicates open is bad that's what causes the re-lock.

Click to expand...

Or opening a door that doesn't have the door lock module problem. My driver rear door doesn't so I end up opening that.

mandrake slink said:

So, with all this extra time not driving anywhere lately and a 2003 Jetta just sitting parked, the electrical parasites drained my battery dead within a week or so. I got it all charged back up and began testing today.



When I connect the meter in-line from battery to the (-) post, after 10-15 seconds it reads 400 mA constant. When I disconnect the interior relay on the battery fuse box. there is no current draw.



Using the TSB 27 08 04, moving to the interior fuse box and with the door open, but latch closed (2 clicks) and doors locked by remote, I am reading that FUSE 14 has 2.3mV drop. This is the only interior fuse that shows any voltage reading across the fuses. The TSB matrix diagram I interpret as meaning 327mA current draw. This fuse 14 is interior lights, central locking system. I keep my interior lights switch in the middle "off" setting, and they usually don't come on at all.



My question is, Now What?!? I assume these results mean that some light somewhere is shorting out? Do I just pull them all out one-by-one until the V drop goes away? Better plan or way to run this troubleshoot? Any comments or links are appreciated. Thanks in advance. Plenty of time to finally figure this out over here...

Click to expand...

Do you have an aftermarket radio?

Here is an excellent video by a forum member on how to track down a parasitic drain. You really need to be looking at amperage draw.

https://www.youtube.com/watch?v=gNTmrwiPe6g

Another direction is the radio amp. My son's Beetle has a problem with the Monsoon amplifier. If he doesn't pull the fuse to it, dead battery in no time.

joep1234 said:

Another direction is the radio amp. My son's Beetle has a problem with the Monsoon amplifier. If he doesn't pull the fuse to it, dead battery in no time.

Click to expand...

^ That usually happens with an aftermarket radio. Monsoon amp won't turn off if not told to. I ended up having to go to a different amp for my radio.

mandrake slink said:

Glovebox light was off when i opened it. I also worked on the glovebox not long ago. Disconnected the light after taking box out and the V drop went away. Battery (-) terminal in-line detection with 10A setting shows 10mA after 10-15 seconds.

Click to expand...

Glove box light light gets power from fuse 1 all the time.
Black / brown wire.

Other side goes to the switch.
Gray / brown.

The switch grounds under the left side of the dash.

joep1234 said:

Another direction is the radio amp. My son's Beetle has a problem with the Monsoon amplifier. If he doesn't pull the fuse to it, dead battery in no time.

Click to expand...

Solution:
https://forums.vwvortex.com/showthread.php?6086643-Solution-to-monsoon-amp-draining-battery

(ignore the vortex kids complaining)

yeah, the parasitic drain is still there. with the meter on 10A setting, inline to (-) and waiting 10-15 secs, it is back to hover around 0.39-0.4 which is a lot. I think:

1) apparent fix I observed earlier was random but at some times it goes down to 0.001 inline at the battery. ALSO AT THIS TIME there was 0.0 VOLT DROP on fuse 14!

2) I see the key needs to be ON to function the glovebox light. Oops! thanks Jokila! Also, my stereo is the stock factory monsoon set and I don't detect any current on any of those fuses.

3) the door locks 30 seconds thing was a Vag-Com setting (AUTO LOCK) The behavior was reset after sitting with no power I guess.

4) door switches on both front doors are borked and have been for a long time. There were also some faults on VAG COM central locking module. I think they were intermittent voltage to all four door locks or something like that. I'd read them now, but the battery is dead again. It takes 3 days or less to die I guess. ShEEESh!

Taken together, I think this means the door switches problem I've had for a long time is a very likely suspect. That these behave erratically as well is in keeping with the apparent erratic solution to the problem I observed earlier. I'm going to double check all the panel fuses again and go from there. Likely tearing the doors down, and its raining today. great...

Have you tried disconnecting the alternator wire at the top of the battery?

Ouch! I just ran a VAG COM auto scan and showed a bunch of Fault Codes. Yikes!! Is this a bad module? Maybe a short in the line of the module? I ran this a day ago and didn't get the passenger locking F221 error. So, now 6 codes here. Hmmmm?

Save it. Clear the codes and see what comes back.
If you disconnected some fuses or the battery itself the modules know it.

mandrake slink said:

2) I see the key needs to be ON to function the glovebox light. Oops! thanks Jokila! Also, my stereo is the stock factory monsoon set and I don't detect any current on any of those fuses.

Click to expand...

I think the light in mine worked w/o the key.
Not positive about it.

It should be hooked to fuse 1.

Some have posted that disconnecting both battery cables and shorting them together for several seconds has cleared some problems.

With you diagnosing keep in mind that some devices in the car do have power for a brief time after exiting the car.
Some for several minutes.

From the low currents in your 1st post I do not think they will be there 5 minutes after removing the key.

Try opening the drivers door and closing the latch with a large phillips screw driver (2 clicks) and waiting several minutes before measuring the fuse drop voltage.

Last, how old is your battery and is it the correct group 94?

I think the CCM will timeout completely after 60 mins (this is why if you leave your interior light on, it will turn off automatically, same with the factory radio). You should wait until then to do battery tests. If you open a door, that timer is reset.

Fuse 4 was blown, the license plate lights. Voltage drop 0.3 mV was detected that would randomly go as high as 3.1mV, sometimes 0.0mV. The computer may actually sense the fuse being inserted by measuring Vdrop on fuse 4's blown contacts (without actually removing the fuse) and waking. Wire harness in the left trunk area was frayed. It had been chopped by the trunk hinge years ago and repaired poorly. I soldered all these wires and shrink sealed. The trunk lock and the trunk switch are on this harness and everything there is good now. Fuse 4 was replaced and I re-performed the TSB_27_08_04_Matrix protocol.

In the sleep state, (connect battery, open door, close latch (2 clicks), lock remote, wait 2 HOURS, YES 2 HOURS!!!) the only vdrop measured now is 0.3-0.4 mV at fuse 14. This corresponds to about 50 mA in the matrix table give or take. This is technically above the nominal sleep current of 40mA for my model. I'm guessing that its okay because its only 10mA difference. Is this actually an okay current measure in sleep?

As well, I have concern about the radio system fuse 42 that was dropping 0.3 mV yesterday when checking (a couple hundred milliamps), but out of the sleeping state probably. Going to unlock car, wait 2 hours with doors closed and then check. We'll see.

Is there a hood position switch on 2003 Jetta? I was concerned open hood affecting the sleep.

Does the computer ever sleep without being locked/armed? I don't usually lock it because alarm goes off sometimes. I guess it wouldn't matter that its awake if the radio/amp didn't draw current improperly. Hmm. I'll repost when I see what fuses are drawing after a few hours unlocked car.

mandrake slink said:

Does the computer ever sleep without being locked/armed? I don't usually lock it because alarm goes off sometimes. I guess it wouldn't matter that its awake if the radio/amp didn't draw current improperly. Hmm. I'll repost when I see what fuses are drawing after a few hours unlocked car.

Click to expand...

I'm pretty sure it does.
If it didn't then there would be more of a current draw.

From your original post:
'electrical parasites drained my battery dead within a week or so.'

How old is the battery and is it the correct group 94?

mandrake slink said:

Is there a hood position switch on 2003 Jetta? I was concerned open hood affecting the sleep.

Click to expand...

If the hood latch is the same part as on my 2002, then there's at least a microswitch on that to tell the alarm system whether the hood is open/closed. it's on the front of the latch - pop the grille off and have a look, it'll be on the left (passenger) side of the latch as you're standing in front of the car looking at it.

Mine recently got stuck in the "hood closed" state, allowing me to arm the alarm with the hood open. Not sure whether there's additional monitoring going on if the hood's left open or not, but you could always use a small screwdriver to push the switch down into the closed position for your test...

Battery is a 2017 AGM Napa legend 9894r. Group 94. 800 CCA. Got the expensive agm charger too. I think my problem is solved once the front door latches get repaired and stop waking the car, calling for internal lights, etc.