[BiturboS4] 2nd Battery in 6 mos.

Ti Kan ti at amb.org
Sun Jan 5 12:26:24 EST 2003

I have left my S4 undriven once for over a month (went on vacation)
and it started right up after I returned, so there is nothing intrinsic
in the S4 that should drain your battery.

To check for total current drain, you need a good multimeter with
current (amp) scale at least 5A (or else risk damaging the meter).
Be sure you have the radio anti-theft code to unlock the radio

Disconnect one of the battery leads and insert the meter into the path
between the battery lead and the battery post.  It should be a small
miniscule amount when the car is parked with all accessories off (DO NOT
try to start the car and be sure key is removed from ignition and all dome
lights are off).  A small amount of current flow is normal for such things
as the clock and remote/alarm circuitry, but I don't expect anything
over 80mA.  That's just a figure I pulled from a hat, I don't know what
a typical S4 should drain while sitting quiescent.

If you have significant current flow, then remove the meter from the
battery, re-connect the battery normally, and then pop open the fuse
box cover on the side of the dash.  Again be sure all accessories including
dome lights are off, and remove one fuse at a time and insert the multimeter
probe in its place.  Look for the circuit that has the current drain in it.
When you have narrowed down to which circuit, when determine which
items are on that circuit and debug it further.  Your owners manual should
list the items but you will probably need the wiring diagram at this point
for the car to do this effectively.

http://www.bentleypublishers.com sells service manual for the S4.

If your car is still under warranty, your dealer should be doing all this
for you.

2003 A4 1.8T multitronic
2001 S4 biturbo 6-sp
1984 5000S turbo
1980 4000 2.0 5-sp
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Laboratories, Sunnyvale, CA. USA
  ///    ti at amb.org
 //////  http://www.amb.org/ti/

dano writes:
> With that degree of electrical drain on successive batteries I think
> it's pretty certain.
> I used to know how to test for this, but can't remember. Check with
> an independent auto electric shop.
> At 3:48 AM -0800 on 1/5/03, Aurangzeb M. Agha wrote:
> >Thanks for the advice JY.  I plan on doing just that.  Very bizarre issue.
> >I wonder if there's something in the S4 which could be causing a battery
> >drain?!

More information about the Biturbos4 mailing list