Checking The Dismantled Alternator; Stator; Rotor - Volvo 164, 1970 Service Manual

Fig . 3-7. Dism a ntlin g the a lterna to r
CHECKING THE DISMANTLED
ALTERNATOR
STATOR
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Check the stO'tor for any short-circuiting. If one or
several of the coils are burnt, there must be a short-
circuit in the stator. Connect a test ·Iamp
(12
V.
2-5
W)
between the stator plates and a terminal on the stator,
see Fig. 3-9.
If t.he lam p lir,hts, the isolation between ;the stator
winding and the sta, t or plates must be burnt out, in
which case the startoT should be r, e placed.
N.B. Only a 12 V, 2-5 W test lamp may be used;
110 or 220 V, D.C. or A.C. lamps may NOT be used.
This applies to all the alternator components.
Check the diodes with a diode tester, see Fig .
3-10.
If any of the rect.ifier diodesis raul;ty, the entire
diode holder (with three diodes) must be replaced.
Fig. 3-8. Removing the drive end shield
3:4
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1044 72
Fig. 3·9. Checking the sta to r
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If any of the isolat' i on diodes is fauHy, replace the
holder, complete with isolation diodes.
If a diode tester is not available, the diodes should
be soldered loose (see page
3-6)
and tested with an
ohmmeter. The diodes should have high resistance in
reverse direction and low resistance in the flow direc-
tion.
ROTOR
Check to make sure that ;the slip rings are not dirty
or burnt.
Check the winding for breakage or damaged isolation.
Measure , t he resistance between the slip rings, see
Fig.
3-12.
At
25 0
C (77
0
F) the resistance should be
4.0
±
0.2 ohms.
Fig. 3-10. Checking the diodes
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