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2001 gls battery drain

02-09-2011, 09:51 PM
Imagine this. Another problem with a 2001 Jetta (4-cylinder GLS) and a parasitic battery drain. Details below, and any insight you can provide would be helpful.

Condition and Tests

* car killed three batteries in two years (no problem starting in summer, but winter breaks them).

* charged existing battery to 12.4 volts, disconnected it, and then reconnected one week later to reveal 12.4 volts. (should be 12.6 at full charge, sure, but only got to 12.4)

* connected battery overnight, 12.4 volts dropped to 11.8, no start.

* same result as above with brand-new battery (including 12.4 volt limit on full charge and subsequent voltage drop).

* multimeter says alternator charging normally (steady reading of 14.5 with car running, tested on both batteries)

* set multimeter to 10 amps, and readings jumped around - 0.5, 0.85, 1.1 - then quit to 0.0 with 10-amp fuse blown (verified with continuity test on fuse pulled from multimeter).

* after three days with battery disconnected, placed a 12-volt test light (0.4-amp draw) in-line, and pulled everything I could think of one-by-one --- all fuses (battery fuses and interior panel), Monsoon audio (radio, amplifier, and CD), and alternator --- but test light (rather bright) would not go out.

Observations (some odd)

* radio retains presets, even with week-long battery disconnect. (unheard of, in my experience)

* CD player, a usual suspect, is factory but installed aftermarket (and removing it didn't make light go out)

* test light glimmered - brighter, dimmer, brighter - not a steady consistent light.

* with fuse 42 (radio, 25-amp) removed, test light would glimmer in sync with loud clicking in the dash behind the odometer: louder clicks = brighter light, quieter clicks = dimmer light.

* glove box, trunk, and interior lights go out when glove box or trunk closed and/or car turned off.

* all auto locks and windows work properly, but can hear what sounds like a window motor trying to wind when doors are unlocked (not CD player).

02-09-2011, 10:59 PM
Do all the bells & whistles work , other than battery drain?
Is there three fuse blocks on this car?
Try isolating the relays!

02-09-2011, 11:56 PM
yep, all bells and whistles work.

two fuse blocks that I could find - (3) 30-amp fuses on battery housing, the few dozen on driver-side inside panel. is there a third?

good idea to isolate relays, but aren't they generally defaulted to "off" position?

two more observations tonite:

* running lights remain on even when the parking break is engaged while car is started or running

* key cannot be removed from ignition unless forcefully placed in 'park' - generally takes two or three times slamming into 'park' to remove key.

TCM maybe?

02-10-2011, 02:24 PM
The fuse should protect the relay and circuits.
Some unswitched relays get the battery with the ignition switch off.
Also some control modules have a capacitor to act as a small battery to give a small battery to the control module to save data and control with the ignition switch off.

If a capacitor is leaking, it could cause drainage on a battery.

Picture the security Alarm ON needing a battery with the ignition switch off!

Because all the bells + whistles works, you might need to Isolate the control modules by
a disconnect.

02-11-2011, 04:16 PM
good advice and explanation.

will try isolating relays and modules with test light (and leave the multimeter out of it) and let you know.

02-11-2011, 04:31 PM
Try to get the Park pos with the ignition key removal problem fixed ASAP!

There might be a broken, or loose sensor/switch, that's not signalling the
TCM your NOT in the parked pos, so you can't have your keys.

02-11-2011, 04:49 PM
agreed. guessing loose sensor or switch and definitely don't want to lose the keys.

02-18-2011, 12:37 AM
thankfully, first thing is that TCM does not seem to be the problem. guessing it's the key - switchblade key has trouble with removal, valet key removes easily under same conditions.

however, testing has revealed additional information.

* re-tested all interior, driver-side fuses against test light, and no problem revealed (test light stays on).

* removing power from S176 fuse/wire on top of battery test light off. this wire send power to the relay.

* isolating relays does not relieve drain on battery - test light continually bright.

* isolating second-from-left 30-amp post at bottom of relay (two red wires) does relieve test light. split those two and have a long list of what works and what doesn't.

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