Alternator fault tracing
Checking the brushes and the regulator
•
NOTICE! Cut the current with the main switch.
•
Remove
all connectors on the alternator. B+, B-, etc.
•
Remove the plastic cover over the diodes. The plas-
tic cover is fixed with two nuts on B1+, B2+, and a
pozidrive screw.
•
Remove the three screws that holds the brushes
and the regulator.
Checking the brushes
•
Measure the length of the brushes between the
brush mating surface and the brush holder. If any
brush is damaged the brushes should be replaced.
Checking the regulator
•
Set 88890074 Multimeter to diode measurement.
•
Connect the probes between the brushes. Check
that there is no short circuit.
•
Switch the probe points and check that there is no
short circuit.
•
NOTICE! If a regulator fault is suspected install a
new regulator and test operate the charge system.
Checking the rotor
•
Set 88890074 Multimeter to diode measurement.
•
Connect one probe to each slip ring. The multimeter
should show low resistance but not 0 ohm (short
circuit) or infinity (open circuit).
•
Check that the slip rings do not have any burn marks
or other damage.
Short circuit test the rotor
1 Set the 88890074 Multimeter to diode measure-
ment.
2 Connect the probes between one of the slip rings
and the stator body. The multimeter should indicate
OL otherwise the rotor has a short circuit.
30-0 General
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