[s-cars] Battery Drain Found & Fixed
landaeta1 at comcast.net
Mon Apr 19 23:59:16 EDT 2004
Great work, thanks - I'll be keeping this write
> -----Original Message-----
> From: Fred Munro [mailto:munrof at sympatico.ca]
> Sent: Sunday, April 18, 2004 8:11 PM
> To: s-car-list at audifans.com
> Subject: [s-cars] Battery Drain Found & Fixed
> Thanks to Tom, Igor, Teddy, Calvin, and Dave for
> responding to my current
> drain question and confirming that the drain was
> indeed too high.
> A bit of work with a digital ammeter isolated
> the problem to the automatic
> window closure circuit. Pulling the A1 breaker
> in the under-hood relay box
> dropped the drain to below 10 mA.
> This circuit is designed to close windows or the
> sunroof if they are open
> when the car is locked. This feature has never
> worked on my car. The circuit
> has it's own relay under the driver's side A-
> pillar kick panel. The power
> supply side is "fused" with a 30 amp breaker in
> the A1 position in the
> underhood relay box. The relay is triggered by a
> white/yellow wire from the
> power window control module.
> This is apparently a relatively common source of
> a battery drain problem -
> it is written up on Scott Mockry's website and
> the recommended fix is to cut
> the yellow/white wire.
> Removing the A1 breaker fixed my problem - this
> disables the auto close
> circuit and leaves the power windows
> operational. From this I assume my
> relay is either fused closed or is indeed being
> activated by the control
> module (via the yellow/white wire) and the power
> drain is in the circuit
> itself somewhere.
> The car now has a 100 mA drain for 30 seconds
> after the alarm is set, then
> it drops off to 10 mA with a spike to 20 mA
> every 5 seconds.
> A substantial improvement from 280 mA.
> When I get some time (ha!) I'll pull the relay
> to check it out.
> Fred Munro
> '94 S4
More information about the S-CAR-List