Piper Warrior III - Page 287

PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL
2D21
24-30-00
PAGE 5
Nov 30/06
CHART 1 (Sheet 2 of 5)
TROUBLESHOOTING ALTERNATOR SYSTEM
Trouble Cause Remedy
Zero output indicated Open field winding Disconnect field terminal of
on ammeter regardless in alternator. alternator from field wiring
of rpm (see alternator and check for continuity
test, 24-30-00). from field terminal to
(cont.) ground with ohmmeter
(20-100 ohms) depending
on brush contact
resistance.
W
ARNING: TURN MAGNETO SWITCH TO OFF BEFORE TURNING PROP.
Pull propeller slowly by
hand turning alternator
rotor through 360° of travel.
If resistance is high, check
brushes for spring tension
and excessive wear and
replace if necessary.
If brushes are good and
field reads open, replace
alternator.
Output indicated on Faulty voltage regulator. Start engine, turn ON load,
ammeter does not meet set throttle at 2300 rpm.
minimum values specified Check voltage at buss bar
in alternator test, 24-30-00. (remove cigar lighter and
check from center contact
(+) to ground (-)). Voltage
should be 27.5 volts
minimum. If voltage is
below this value, replace
regulator.
High resistance connections Check visually for loose
in field or output circuit. binding posts at the various
junction points in system,
alternator battery post, lugs
on ammeter, connections at
voltage regulator, circuit
breaker, etc. (See wiring
schematic, Chapter 91.)
Examine crimped terminal
ends for signs of
deterioration at crimp or
strands of broken wire at
crimp. Tighten any loose
binding posts or replace
bad wire terminals.