Battery drain

vanagonjon

Well-known member
Joined
Sep 22, 2007
Location
Pelham, MA
TDI
96 Passat Wagon
So I am trying to track down a drain that kills my battery after a few days of sitting on my 97 B4V GLX conversion. I disconnected the battery and put a test light in series between the cable and the lug. I removed all the fuses (at the same time) under the dash but the drain was still there. I pulled the alternator wire to no avail. I also pulled the 20A fuse and adjacent bar fuse from the box above the bat but no fix. The leak is about 30 mA.

I pulled the individual small terminals from the positive battery wire terminal and found the leak to be coming from the largest of the four wires.

Now the things to note are the power windows always work, even when the key is out of the ignition. This may be related to a water leak from the sun roof drain. Also, I found the glow plug fuse (the bar fuse next to the N75 solenoid) was blown, and the housing was fried.

Thank you in advance help in solving this pesky gremlin.
 

Jack Frost

Veteran Member
Joined
Nov 30, 2007
Location
Rural Manitoba
TDI
2009 Clean Diesel
I don't know what the normal draw on the battery for your car when it is shut off, but the 2009+ cars draw 100 ma. I have had mine parked for a few weeks and it still started. So I don't know why 30 ma would be draining your battery in a few days.:confused: Maybe you should check out the battery.
 

Joe_Meehan

Top Post Dawg
Joined
Sep 3, 2005
Location
Ohio USA
TDI
NB TDI, 2002.5, Silver
I agree with Jack. Many autopart stores will check the battery and the charging system for free. Not a bad idea.
 

veedubyoo

Veteran Member
Joined
Feb 18, 2010
Location
Page, AZ
TDI
96 Passat TDI Variant
I don't know what the normal draw on the battery for your car when it is shut off, but the 2009+ cars draw 100 ma. I have had mine parked for a few weeks and it still started. So I don't know why 30 ma would be draining your battery in a few days.:confused: Maybe you should check out the battery.
VCDS has a "Transport Mode" function that will put a late model(not sure of the years) to sleep so they don't draw down the battery. Wonder if it can practically be used when letting a car sit for weeks.
 

veedubyoo

Veteran Member
Joined
Feb 18, 2010
Location
Page, AZ
TDI
96 Passat TDI Variant
Why not try removing each fuse in succession while measuring the draw till you find the circuit that is responsible then continue from there.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
30ma X 24 hours X 3 days = 2.16 amp-hours. I have an 80 amp-hour battery. What do you have?

Check the draw, and if it's 30 ma, it could be normal for the radio and security system. I'd double check the draw, and if it's that low, I'd be checking the alternator and battery.
 

vanagonjon

Well-known member
Joined
Sep 22, 2007
Location
Pelham, MA
TDI
96 Passat Wagon
30ma X 24 hours X 3 days = 2.16 amp-hours. I have an 80 amp-hour battery. What do you have?

Check the draw, and if it's 30 ma, it could be normal for the radio and security system. I'd double check the draw, and if it's that low, I'd be checking the alternator and battery.
I must have read the meter wrong. I've never used it in amp mode until now. It must have been 300 mA.

This is not a problem of insufficient cranking amps (the measure of a battery test). If the car sits for a day it will start fine, even if it is 10 F out. However, after a week of sitting the voltage is so low the dome lights wont come on.

The first thing I did was to pull each fuse sequentially. When the test light didn't go out I pulled all the fuses at the same time to ensure the drain wasn't in more than one fused circuit. The drain on the battery is the same with or without the fuses in place.

A friend of mine thinks the ignition switch might be malfunctioning since the window circuit doesn't shut off. I will buy a replacement switch since they are cheep and see if it kills the drain.

Thanks
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Amp-hours is an important measure in tdi batteries. If you were a factor of 10 off, you should still have 3/4 of the power in an 80 amp-hour battery. What is under your hood? In amp-hours?
 

vanagonjon

Well-known member
Joined
Sep 22, 2007
Location
Pelham, MA
TDI
96 Passat Wagon
I'm not sure. The battery is a 41 series that I bought from walmart. I bought an ignition switch since they are cheep and is the likely cause for the fault. I broke my leg last week so dont be surprised if it takes me a little while to get to replacing it.
 

vanagonjon

Well-known member
Joined
Sep 22, 2007
Location
Pelham, MA
TDI
96 Passat Wagon
Ricosuave, that was the first thing I did as I mention in the title post. I have years of automotive repair experience so I am familiar with the basics. This problem isn't as simple.

I am still off my feet and I'm not driving the car so I haven't looked at it in a while.
 

Diesel_1000

Active member
Joined
Jun 2, 2009
Location
pa
TDI
JETTA
Most likely the battery drain is comming from a short circuit in the car. Start by the most abvious place the boot covering the electrical wires in door jamb. Use a good flash light to check all the doors for any electrical problems.
 

bikeprof

Veteran Member
Joined
Sep 2, 2005
Location
Pagosa Springs, Colorado(YEAH!)
TDI
1996 Passat B4 Variant white, 1996 Town & Country 3.8 LXI
Could be one of the door jamb push-ins, the cigarrette(is this the way to spell this pesky habit?), lighter or maybe the fan switch?

Once I open the doors with the key off, the auto window cuts off...
 
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