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Parasitic Draw? ... or something else


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VWnightmare
Novice

Dec 30, 2013, 5:32 PM

Post #1 of 14 (1213 views)
post icon Parasitic Draw? ... or something else Sign In

I have a 1999 Volkswagen Jetta 2.0L with about 155000 miles. For the past couple of years I have had some battery issues. Early 2012 I was gone for a couple months and left the car to the wife, she doesn't like the car so didn't drive it like i told her to and the battery died so when i returned in May 2012 i had to replace the battery. From then until January 2013 i didn't have too many issues because I was driving it pretty much 5 days a week every week and not letting it sit for more than a week without starting it. Again in January 2013 I have to leave and the wife is in charge of the car. She left the car at home for 2-3 weeks while she was on vacation and returned to a car with a dead battery, couldn't be jumped, took it to autozone and they said it was a bad battery and since it was less than a year they replaced it for free. And now fast forward to December 2013 I let the car sit for about 1.5 weeks while i was on vacation, only to get up to head to work to find that my car battery was completely dead. I was able to get it to start by jumping it but it took a while, I let it run for 30-45 minutes, shut it off tried it again later and it wouldn't start again. Took that battery into autozone they hooked it up to the charger for about an hour then run their test to find it said bad battery again, and again they replaced it for free.

Ok so that's the back story and here is the information I have for today after doing a battery discharge check (disconnecting negative battery cable from battery, connecting multimeter to battery cable and battery post):
Ok so I made sure the key was out of the ignition, all acc. off, doors all closed, no hood light, hooked up my multimeter and the numbers jumped around for a little while. It would peak at about 1.2A, the average was around 250-330mA until finally settling at 40mA. The process took about 30 seconds. I did it multiple times (probably 5-6 and took about the same amount of time each time).

So was thinking that maybe the initial peaking was just computers initiating with power and what not, but 1.2A seemed pretty high even for that.... but then it eventually settled to 40-50mA which is well within normal range for my car being off. But i decided to do a little poking around anyways and removed the 2 fuses for my radio (fuse 37 and 42).

With both fuses removed the check peaked at about 340mA and only took about 5 seconds to settle at 10mA. So then i decided to put in one fuse at a time, starting with fuse 37, ran the check and it stayed the same (taking about 5 seconds and settling at 10mA). So then i remove fuse 37 and put in fuse 42 and run the check. Now we are back to what we were in the beginning taking about 30 seconds to finally settle to a reasonable 40-50mA, but still peaking high over 1A Unimpressed

One last piece of information, I did an open circuit voltage test on my battery. Car off and its sitting at 12.6V (better be its a new battery!). Start the car up, let it run for a couple minutes and do the test again and its sitting at around 14.3V ...so Alternator seems to be working is that correct?

So now my subject line.... Parasitic Draw?...or something else draining my battery?


Hammer Time
Ultimate Carjunky / Moderator
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Dec 30, 2013, 6:29 PM

Post #2 of 14 (1201 views)
Re: Parasitic Draw? ... or something else Sign In

Here is how you have to approach this.

You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
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Dec 30, 2013, 6:39 PM

Post #3 of 14 (1196 views)
Re: Parasitic Draw? ... or something else Sign In

HT, I think he gots the idea on how to check for parasitic draws.

According to service information maximum draw is 25mA.

Alternator charging voltage looks good.

You should have your meter connected and monitoring draw for longer than 30 secs. It may take up to an hour for everything to go to sleep. Also if this has a hood switch, make sure it is closed.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Dec 30, 2013, 6:43 PM)


VWnightmare
Novice

Dec 30, 2013, 7:09 PM

Post #4 of 14 (1189 views)
Re: Parasitic Draw? ... or something else Sign In

I'll run it again tomorrow morning double checking that everything is off including hood switch and ill let it go for 30-60 minutes and will report back. also my manual says anything under 100mA is good


Hammer Time
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Dec 30, 2013, 7:17 PM

Post #5 of 14 (1187 views)
Re: Parasitic Draw? ... or something else Sign In

No, I don't think he was doing things correctly and that is why I posted the procedure.
He had all the fuses removed at once.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
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Discretesignals profile image

Dec 30, 2013, 7:18 PM

Post #6 of 14 (1186 views)
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100mA may be too much. General rule is less than 50mA, but that isn't set in concrete. Some vehicles may have more and less depending on how their system is designed. Let us know what you find out.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


VWnightmare
Novice

Dec 31, 2013, 9:35 AM

Post #7 of 14 (1163 views)
Re: Parasitic Draw? ... or something else Sign In

So I'm running the check again for a longer period of time.... The first time I did it I had all the fuses in. When i was doing troubleshooting i decided to start with my radio, which is why i took 2 fuses out because they are both to the radio, and then like i said i ran the test some more with only one of them out at a time to narrow it down to a specific fuse. As of right now I can't leave my door open because unlike most cars the VW Jetta doesn't have a plunger for a door switch that I can just depress, it is internal to the handle so Haven't figured out how to do it yet. But as soon as I finish with the test I'm running now Ill repost again with results


Hammer Time
Ultimate Carjunky / Moderator
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Dec 31, 2013, 9:41 AM

Post #8 of 14 (1162 views)
Re: Parasitic Draw? ... or something else Sign In

You can't test for draw unless you can close the door switches. You should be able to just close the latch as it would be with the door closed. Every time the door is opened, you activate the timers again.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Dec 31, 2013, 9:41 AM)


VWnightmare
Novice

Dec 31, 2013, 10:16 AM

Post #9 of 14 (1157 views)
Re: Parasitic Draw? ... or something else Sign In

Ok, ran the initial check for an hour, door closed, all acc. off.... other than the first ~30 seconds where I'm assuming the initial timers were doing their thing, it stayed at 40-50mA the whole time.

Also looks like I can just mechanically close the switch on the door to make it think it is close.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 31, 2013, 10:28 AM

Post #10 of 14 (1156 views)
Re: Parasitic Draw? ... or something else Sign In

That would be normal. Sounds like you have no draw.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



VWnightmare
Novice

Dec 31, 2013, 10:54 AM

Post #11 of 14 (1154 views)
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Yea... any ideas as to why I'm going thru so many batteries then?


GC
User
GC profile image

Dec 31, 2013, 12:38 PM

Post #12 of 14 (1144 views)
Re: Parasitic Draw? ... or something else Sign In

Do you have any aftermarket equipment in this vehicle? E.G. stereo system, power inverter? What has the outside temp been when this happened? Here in Michigan when it gets single digits and subzero at night, you better have a top notch battery if you plan on letting it sit for more than a couple days.


____________________________________________________
Willing to help, willing to learn... Rob

(This post was edited by goiserclause on Dec 31, 2013, 12:41 PM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 31, 2013, 1:24 PM

Post #13 of 14 (1139 views)
Re: Parasitic Draw? ... or something else Sign In

Have you tried disconnecting the battery overnight to see if it makes a difference?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



VWnightmare
Novice

Dec 31, 2013, 3:50 PM

Post #14 of 14 (1130 views)
Re: Parasitic Draw? ... or something else Sign In

As far as I can tell, everything is stock. And the temps haven't been any lower than upper 20's for the past couple months (and that's on the coldest of nights here) I think the week that i let it sit the coldest it got was 32.






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