# Battery drain



## Sean in SC (Feb 25, 2009)

I have a 2001 TT Coupe 225hp AMU that keeps draining down the battery when parked. Has anyone had a similar issue?


----------



## jzobie (Jun 8, 2008)

Mine did when the comfort control module got fried from water leaking in. How long does it take to drain the battery when parked?


----------



## Morio (Feb 16, 1999)

It could be your voltage regulator going out.... Mine was having the same issue but thought it was because of all my audio and air ride... come to find out it was the voltage regulator:wave:

I was able to replace without removing the alternator:thumbup:


----------



## lite1979 (Sep 9, 2005)

Since he has a coupe, it's less likely that it's the CCM.

I solved my battery drain with a multimeter last year.

Step 1: Car off, everything else turned off, trick the car into thinking it's closed with the door open and get access to the fuse panel.

Step 2: Remove your negative or positive battery cable (I prefer the negative post, but since we're measuring for amps, it shouldn't matter)

Step 3: Set your multimeter to amps; you'll want the fuseless circuit, so you may have to move your lead to the appropriate place on the multimeter

Step 4: Put one lead on the bare battery post, and the other lead on the disconnected cable end (I had my girlfriend hold my leads on their respective spots and watch the multimeter to save time)

Step 5: Wait for the car to shut off (dome lights off, radio off, car thinks door is shut)

Step 6: Narrow down your current draw to a circuit by pulling fuses one at a time until the draw becomes less than .05A. Search this circuit for shorts to ground and repair/replace the wire/component as necessary.

We narrowed mine down to fuse 42, which is the radio/amp fuse on our car (same year and motor here). After pulling fuse 42 my battery stopped draining, but I had no radio. Later last winter I did my heater core, and while I had the dash apart, I noticed a few wires that led to the back of the head unit had no insulation around them (they originally had a foamy wrap around them, but it had since deteriorated and all but vanished). I wrapped the bare wires (one was a small nut and bolt junction) with electrical tape, put fuse #42 back in, and have been enjoying my radio every since with no battery drain(well, I need a new door speaker, but hey).

If you narrow yours down to the head unit/amp, the tool is super cheap to pull the stereo, and a few torx bolts and that entire area is pretty easy to dismantle.


----------



## Sean in SC (Feb 25, 2009)

Thanks for the guidance! I'll let you know what I find.


----------



## Sean in SC (Feb 25, 2009)

My problem is definitely in the stereo wiring. Before I pulled that fuse I could hear a constant tapping noise from the vicinity of the CD changer. There was an aftermarket receiver already installed when I bought the car. The CD changer has never worked, so I assumed it was not connected. Apparently I was mistaken. The CD cartridge will not eject from the changer, and I don't see any sign of life from the unit, but I can't imagine anything else in that area that would be making a repetitive tapping noise.
Now that I have the stereo circuit fuse removed, the battery drain issue seems to be eliminated. But now my driver's side window doesn't cycle down & up when I open the door. The window still goes up and down with the switch. The passenger side window still operates normally. Weird.


----------



## gearheadzTV (Sep 15, 2009)

Sean in SC said:


> But now my driver's side window doesn't cycle down & up when I open the door. The window still goes up and down with the switch. The passenger side window still operates normally. Weird.


Try resetting the auto window, iirc you just hold in up position for a few seconds after it goes up.




lite1979 said:


> Since he has a coupe, it's less likely that it's the CCM.
> 
> I solved my battery drain with a multimeter last year.
> 
> ...


Gonna have to give this a shot in a last effort to keep the TT. It's annoying that every time I want to take her out the battery is drained. That and my dome lights died for some other unknown reason...


----------



## Sean in SC (Feb 25, 2009)

The reset procedure fixed the window glitch. Thanks for the help! 

As for the battery issue, for now I'm keeping the stereo fuse out and enjoying the sound of my screaming turbo and growling exhaust (along with an assortment of rattles and squeaks, of course). Does anyone know if the power for the CD changer comes from the receiver or from a separate power source? Getting to the changer itself looks like a severe pain.


----------



## lite1979 (Sep 9, 2005)

Power to the CD changer is on the same circuit as the radio/amp, but I've never heard of the CD changer being the culprit of a battery drain in our cars. It's a little scary getting to it, since you have to start at the back of the car and move forward removing interior pieces, but it's not impossible. Have you used a multimeter yet to measure your amperage draw with the radio fuse in? I would do that, and wait for the CD changer to stop checking for CDs first, then see what the draw is. It'll jump up to .65 or so while checking for CDs, but should drop down to .05 after a while if everything is working properly. Do the multimeter test and be very patient, since it takes a while for the car to come to rest. When I fixed my bare wires, I had to wait for the changer to stop checking the CDs to be sure I had fixed my problem.

Also, have you checked behind the head unit yet? There is a rat's nest of wires back there, and you likely have some missing insulation like I had. Bad splicing/wrapping by the PO with the aftermarket stereo could be your problem.

Do you have a cartridge of CDs in the changer or no? It might not be seated in the changer all the way, or the release tab on the cartridge may be stuck. Still, if the changer has power, it should push the cartridge out. Was there ever a Phatbox installed in your car?


----------

