BMW 5251 Service Manual page 374

121-8
/Battery, Starter, Alternator
NOTE-
Automatic transmission cars: ambershifier
LED
willgo out at
consumer cut-off.
4
Attach closed-circuit current measurement adaptor
(BMW special tool 61 2 300):
Connect red clamp (marked
A
-BATT (+)) to positive bat-
tery terminal.
Connect black clamp (marked B -CHASSIS) to chassis
ground point.
NOTE-
Green
LED
will light up to indicate correct installation of
closed-circuit current measurement adaotor.
<
Connect blaclc clamp (marked B
-
BATT (-)) to negative bat-
tery terminal. Green LED light will go out.
NOTE-
Any electrical overloading will be indicated at this point by
lighting the red
LED.
If the red
LED
lights up, check the adap-
tor connections.
<
Set multimeter (A) to 10 amp measuring range and connect
it to adaptor.
NOTE
-
Set multimeter to record average readings.
Ifpossible, turn offpowersaving features of multimeter
which prevent a long term (overnight) test by automatically
powering down meter.
-
Disconnect battery ground strap
(B)
at chassis mounting
point.
-
Measure closed-circuit current using multimeter.
-
Typical average closed-circuit current for
E39
vehicles is
40 mA. Readings over 50 mA must be further investigated.