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Discussion Starter · #1 ·
Hello.
I have problem with my wagon passat. 1.9tdi engine and year is 2000
Basically I was wondering why the battery is dead every morning. Mesured the current and its shows me almost 0.8A.
Started pulling fuses and when fuse #14 and fuse #38 is removed, drain is 0.06A so 60mAh
Thats much better than the 0.8A I got.

Started looking for wires and stuff where they go and when I remove fuse #14, current drops to 0.4 and when I remove #38 It drops to 0.06

I disconnected every door and removed every light and stuff I had. Radio is removed and everything aftermarket.
So what do I do next?
Now I have every door connected back but driver side left side I removed one blue plug. And it dropped to 0.06A

With that plug removed car dosent have power anywhere inside.
Any advice? I have been looking for wires and stuff for 3 days.

I'll soon make timer with relays that when I put key in, then everything got power and after I remove the key timer starts timing and after sometime it disconnects the battery so It wont drain it

Oh yeah, and the battery is good for 100%
 

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check any relays (you will have to open them up) which operate on that fused circuit for contacts which are fused/welded together from heat/drain on the circuit, I assume you have not put bigger fuses in any of the circuits....
 

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Discussion Starter · #3 ·
Funny thing is that every single relay is removed, in the cabin and from ecu. even the ecu is disconnected.
 

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Just to rule it out, you might also disconnect the alternator, which might draw current like that if a diode was faulty. However, your 0.8A drain is about 10 Watts, enough to make something warm to the touch.
 

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Well, you've narrowed it down to the Comfort system (CCM & doors), by removing fuses 14 & 38 (which are the two power supplies to the CCM.)
One point to make, though: You can't jump straight to measuring draw on these - need to first wait for the CCM to 'go to sleep' (~ 20 minutes of not touching the car.) Any measurement prior to that time is invalid.
Also, least-invasive methods (read: not disturbing anything) generally get you results faster. Unplugging things can wake other things up.

With every fuse installed:
Open all four doors, leave unlatched. Open the tailgate, and leave it unlatched. When the CCM shuts down (all interior lights will turn off), recheck your draw.
If you're using a clamp-on ammeter (which would be best), go check the power supply wire at each door - if it's one of them, you should see it.

I'd need to re-check my Bentley's diagrams, but... I think that blue connector is for the dash harness, not the door. Unplugging a door shouldn't kill the car. Unplugging the dash harness would.
 

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Discussion Starter · #6 ·
Well, you've narrowed it down to the Comfort system (CCM & doors), by removing fuses 14 & 38 (which are the two power supplies to the CCM.)
One point to make, though: You can't jump straight to measuring draw on these - need to first wait for the CCM to 'go to sleep' (~ 20 minutes of not touching the car.) Any measurement prior to that time is invalid.
Also, least-invasive methods (read: not disturbing anything) generally get you results faster. Unplugging things can wake other things up.

With every fuse installed:
Open all four doors, leave unlatched. Open the tailgate, and leave it unlatched. When the CCM shuts down (all interior lights will turn off), recheck your draw.
If you're using a clamp-on ammeter (which would be best), go check the power supply wire at each door - if it's one of them, you should see it.

I'd need to re-check my Bentley's diagrams, but... I think that blue connector is for the dash harness, not the door. Unplugging a door shouldn't kill the car. Unplugging the dash harness would.

Thanks for replay.
I removed 14 and 37 fusesr and waited 24h at least and current draw was still.
When I unplug the blue plug thers no power on the car.
When I unplugged every door The current draw did not stop.

Now I did put every fuse back and plugged the blue plug again to car. Car started fine but thers was alot of current draw after 1h sitting doors unlocked BUT The thief alarm went off and did not stop until I disconnected the battery. I tried locking and unlocking car and the alarm did not stop.

Im out of ideas.

Basically im at point again where car is stock, every fuse is in their place. every wire is connected back.
I want to start from the start. Where do I start and what I start checking? After I figure out how to shut down the thief alarm.
 

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You were asking for trouble when you disconnected so many things, especially having them all out at the same time.
It appears that you have put something back in the wrong place or dislodged something, causing the alarm problem.
I suggest you double check that you have the correct relay in position 12 on the 13 pos relay carrier.

Then run a full scan with VCDS and post the codes.
 

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Discussion Starter · #8 · (Edited)
You were asking for trouble when you disconnected so many things, especially having them all out at the same time.
It appears that you have put something back in the wrong place or dislodged something, causing the alarm problem.
I suggest you double check that you have the correct relay in position 12 on the 13 pos relay carrier.

Then run a full scan with VCDS and post the codes.
I know for sure that every relay and fuse is in correct place, I took pictures before I removed them. I am electrical engineer so I know how stuff works but no idea about car electricity. If I can get some wiring diagrams then that would be bueno

Got the thief alarm system sorted and now the alarm wont go off randomly :D

But problem is still why the current draw?
Everything is at right place, I locked all doors, waited 2h and mesured 0.6A
 

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With the interior lights set to the door position, do they switch off after the door is shut ? (within about 20 seconds)
Check the glove box and trunk lights. You will need the wiring diagram to properly track this down.
 

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Discussion Starter · #11 ·
With the interior lights set to the door position, do they switch off after the door is shut ? (within about 20 seconds)
Check the glove box and trunk lights. You will need the wiring diagram to properly track this down.
yes, every light will switch off after like 20sec. And when I open the door they will swtich on
 

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I was caught out once by an always-on glove box interior light. Hard to see with the glove box door closed. Solved it by removing the bulb.
 

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Discussion Starter · #14 · (Edited)
I’m going to refer you to this legendary thread, where in the end it seems a bad battery was ultimately the source of similar gremlins. As you can see, parasitic drains like this shouldn’t drain the battery fully overnight, so measure twice on teh battery and charging system to confirm goodness.
http://www.passatworld.com/forums/b5-garage/373706-parasitic-drain-battery-linked-fuse-14-37-a.html
I have actually 5 batteries in the car. All of them are fine. The car is build for subwoofers so thers enough batteries and all batteries are good.
I have tested them one by one.
Also the charging is good.

I charge those batteries for one night with battery leads disconnected. So they are full. after one night the car wont even cranck and I have to charge for 2 hours to just get it started. I know that like 300mA would take few days at least to drain good battery.
But I have seen like 1.5A draw and 0.6A. It changed alot. Most of the time its 0.8A
fuse 38 takes like 0.3A and fuse 14 also something like that. Even after 1h of sitting they still draw current. and also central lock and power windows power wire takes 0.2A-0.4A


I was caught out once by an always-on glove box interior light. Hard to see with the glove box door closed. Solved it by removing the bulb.
I have glove box light unplugged, and I have removed every light inside the car, even from doors.
Its not the problem
 

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It is not possible for all that you have stated to be correct.
I suspect that one or more of the batteries is/are likely faulty.

1) Remove all extra batteries and leave them out until this problem is resolved.
2) Get the normal battery fully charged and load tested.
3) What is the battery voltage with the engine running ?
4) what is the battery voltage 15 minutes after running ?
 

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At 1.5A (18 Watts), something is getting fairly warm. I wouldn't just measure voltage, I'd use my hands, or better yet, and IR detector.
 

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Discussion Starter · #17 ·
It is not possible for all that you have stated to be correct.
I suspect that one or more of the batteries is/are likely faulty.

1) Remove all extra batteries and leave them out until this problem is resolved.
2) Get the normal battery fully charged and load tested.
3) What is the battery voltage with the engine running ?
4) what is the battery voltage 15 minutes after running ?
I did load test yesterday at local workshop. Looked good
engine running voltage is 14.5
after 15min or so its 12.7
after 2h its 11.8
 

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You mentioned you disconnected the radio, but what about the amp(s) that you must have to drive your multiple subwoofers?

This is easily more exciting than a classic Scandinavian whodunit detective thriller.
 

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I did load test yesterday at local workshop. Looked good
engine running voltage is 14.5
after 15min or so its 12.7
after 2h its 11.8
11.8 is much too low for two hours later.

Either the battery wasn't fully charged before you began, and/or the battery is defective, and/or the car still has a significant parasitic drain.
 

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Discussion Starter · #20 ·
You mentioned you disconnected the radio, but what about the amp(s) that you must have to drive your multiple subwoofers?

This is easily more exciting than a classic Scandinavian whodunit detective thriller.
ofc I have disconnected all the aftermarket stuff and tested with one battery.
 
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