Piper COMANCHE PA-24-180 Service Manual page 640

PIPER COMANCHE SERVICE MANUAL
TABLE IX-VII. TROUBLESHOOTING (cont)
Cause Trouble
Remedy
Generator operaung
within rated speed
range but voltage
output low. (cont)
Shorted or open armature
coils.
Replace generator or arm-
ature.
Improper operation of the
voltage regulator.
Adjust regulator.
Generator operating
within rated speed
range but voltmeter
indicates zero.
Wiring not properly
connected.
See electrical system wiring
diagram.
Grounded or open field
coil assembly.
Remove the generator and
replace with one known
to be in good condition.
Generator operating
within rated speed
range. but voltage
output is erratic.
Excessive sparking at
generator brushes.
Generator operating
within rated speed
range but system am-
meter reads off scale.
System ammeter fluctuates
excessively when in-
dicatmng rated load.
Unstable operation of
the voltage regulator.
Same as "Generator
operating within rated
speed range but voltage
output low", above.
Same as "Generator
operating within rated
speed range but voltage
output low", above.
Generator field magnetized
in the wrong directon.
Generating system is over-
loaded.
Replace voltage regulator.
Use remedy under "Gen-
erator operating within
rated speed range but
voltage output low",
above.
Use remedy under "Generator
operating within rated
speed range but voltage
output low", above
Flash field with a jumper
wire on regulator between
generator and battery.
Check the system for
abnormal loads.
Improper operation of gen-
erator reverse-current
relay.
Loose connections.
Readjust to operate properly
Tighten connections.
ELECTRICAL SYSTEM
ISSUED: 8/18/72