Battery. Starter. Alternator; Special Tools; Engine Electrical System - BMW 5251 Service Manual

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Battery, Starter, Alternator
This section covers the battery, alternator, starter and associ-
ated components of the electrical system.
Troubleshooting information forthese components isfound in
Table a. Battery, alternator and starter troubleshooting.
For additional electrical troubleshooting information, see
600 Electrical System-General.
Special tools
4
Automotive digital multimeter
CAUTION-
Only use a digital multirneter when testing automotive electri-
I )
cal components.
4
Closed-circuit current measurement adaptor
(Tool No. BMW 61 2
300)
Engine electrical system
The alternator and starter are wired directly to the battery. To
prevent accidental shorts that might blow a fuse or damage
wires and electrical components, always disconnect the
negative (-) battery cable before working on the electrical
system.
Various versions of alternators, voltage regulators, starters,
and batteries are used in E39 cars. Replace components ac-
cording to the original equipment specification.