Piper SARATOGA PA-32-301 Maintenance Manual page 194

PIPER AIRCRAFT
PA-32-301/301T
MAINTENANCE MANUAL
STATOR GROUND AND NEGATIVE DIODE TEST.
- CAUTION-
DO NO T use digital ohmmeterfor this test, because it will give false
indications.
1. Set the ohmmeter selector switch on resistance scale 10 and zero meter.
2. Connect one lead to the "STA" terminal and the other lead to the "GRD" terminal. A reading of
approximately 60 ohms should be obtained in one direction and an infinite reading (no needle movement) in
the other direction. Reverse leads and check in opposite direction.
3. A reading of 60 ohms or less in both directions indicates:
A. A defective negative diode.
B. A grounded positive diode plate.
C. A grounded alternator "BAT' terminal.
D. A grounded "STA" terminal.
E. A grounded stator winding (laminations grounded or windings grounded to front or rear
housing).
4. Infinite readings (no needle movement) indicates an open "STA" (Stator) terminal connection.
FIELD CIRCUIT OPEN OR GROUND TEST.
1. Set ohmmeter selector switch to resistance scale 1 and zero meter.
2. Connect one lead to the "FLD" terminal and the other lead to the "GRD" terminal.
3. Spin the pulley and note ohmmeter reading. Meter should read between 4 and 200 ohms and fluctuate
while rotor is turning.
4. A reading lower than 4 ohms indicates:
A. A grounded positive brush.
B. A grounded field terminal.
C. A defective rotor.
5. A reading higher than 200 ohms indicates:
A. Worn out or hung brushes.
B. An open brush lead.
C. A defective rotor.
EFFECTIVITY: FORD
24-32-12
Page 24-29
Added: August 23, 1982
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