Piper Arrow IV Turbo Maintenance Manual page 190

CHART 2401. TROUBLESHOOTING (ALTERNATOR) (cont)
Trouble
Zero output indicated on
ammeter regardless of RPM.
(Refer to alternator system
test procedure.) (cont)
Output indicated on am-
meter does not meet min-
imum values specified in al-
ternator system test pro-
cedure.
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
Cause
Open field winding in
alternator.
Faulty voltage regulator.
1H22
Remedy
Disconnect field terminal of
alternator from field wiring
and check for continuity from
field terminal to ground with
ohmmeter (20-100 ohms) de-
pending on brush contact re-
sistance. (Pull propeller
slowly by hand turning alter-
nator rotor through 360°
of travel.)
—CAUTION—
Turn magneto switch to off
before turning prop.
If resistance is high, check
brushes for spring tension
and excessive wear and re-
place if necessary. If brushes
are okay and field reads open,
replace alternator.
Start engine, turn on load (re-
fer to alternator test pro-
cedure), set throttle at 2300
RPM. Check voltage at buss
bar (convenient check point,
remove cigar lighter and
check from center contact (+)
to ground (-). Voltage should
be 13.5-volts minimum. If
voltage is below this value,
replace regulator.
24-02-00
Page 24-03
December 1, 1978