Piper Cherokee Six Service Manual page 577

371
END VIEW
SIDE
VIEW
Figure 10-24m. Brush Installation
Figure 10-24n. Internal Wiring Schematic
10-271. CHECKING ALTERNATOR BELT TENSION. If properly installed, tensioned and
checked periodically. the alternator drive belt will give very satisfactory service. However, an
improperly tensioned belt will wear rapidly and may slip and reduce alternator output.
Consequently. a belt should be checked for proper tension at the time it is installed. again
after 25 hours operation and at each 100 hour inspection thereafter.(Referto
Paragraph
10-32.) For aircraft with airconditioning installed refer to Paragraph 13-22 & 13-23 for
alternator belt tensions.
10-28. VOLTAGE REGULATOR.
10-29. CHECKING VOLTAGE REGULATOR. The regulator is a fully transistonzed unit
in which all of the components are encapsulated in epoxy, which makes field repair of the
unit impractical, and if it does not meet the specifications, it must be replaced. The
regulator may be tested by the following procedure:
a. Be sure that the battery is fully charged and in good condition.
b. Check the alternator according to the manufacturer's instructions, to determine if it
is functioning properly. This test must be done with the regulator out of the circuit. After
completing this test, reconnect the regulator into the circuit.
c. Use a good quality accurate voltmeter with at least a 15 volt scale.
d. Connect the positive voltmeter lead to the red wire at the regulator harness
connector, or terminal block. Connect the negative voltmeter lead to the regulator housing.
(Note) Do not connect the voltmeter across the battery, because the regulator is designed to
compensate for resistance contained within the wiring harness.
e. With the alternator turning at sufficient rpm to produce a half load condition, or
approximately 25 amperes output, the voltmeter should read between 13.6 and 14.6 volts.
The ambient temperatures surrounding the voltage regulator should be between 50 F. to
100
°
F. while this test is being made.
ELECTRICAL
SYSTEM
Revised: 8/14/73
PIPER CHEROKEE SIX SERVICE MANUAL
3C1