Bosch WPG 012.00, Operating Instructions Manual

Page: 11 / 24

11
A B C
Pointer in green area for all 3
measurements:
Diodes OK. No deflection:
Diode defective (short cir-
cuit)
Pointer in red area:
Diode has open circuit.
(Test again as individual di-
ode after unsoldering.)
Resistance values equal for all
3 measurements:
Stator winding OK. Resistance values not equal:
Stator winding has interturn
short circuit (unsolder leads
and test with measuring brid-
ge).
If connection to the collector rings is impossible, connect to
DF and ground. However, due to contact resistances measu-
rement produces higher values which fluctuate as the rotor
turns. Note:
Ask vehicle manufacturer for
rated values.
Diode Ok if
measurement
1
= full
deflection
measurement
2
= max.
0.8 mA
No deflection:
Diode defective (open cir-
cuit) Diode defective if
measurement
1
and
measurement
2
show full deflection (short cir-
cuit).