Piper Navajo PA-31 Service Manual page 772

PIPER NAVAJO SERVICE MANUAL
NOTE
If the similar optional radio lights need servicing, refer to the
Avionics Wiring Diagram Service Manual for the appropriate
wiring information. (See Section XII.)
11-147. REMOVALOFSOLID
STATE DIMMERASSEMBLY. (Serial Nos. 31-
7
512046to
31-7812129.) The potentiometer is located on the overhead switch panel, with the
potentiometer shaft projecting through the royalite panel. The dimmer unit is located on the
radio sheft aft of the forward baggage compartment.
a.
Remove the screws securing the royalite trim panel containing the overhead switch
panel and let hang.
b. Remove the knob from the variable resistor which controls the dimmer that is being
removed.
c. Remove the nut securing the variable resistor to the front of the panel.
d. Remove the variable resistor from the panel.
e.
Disconnect the electrical harness for the variable resistor and remove variable
resistor.
f.
Remove screws securing radio shelf access panel, remove access panel and locate
dimmer unit.
g. Disconnect electrical harness connector for the dimmer unit.
h. Remove the screws securing the dimmer unit to the radio shelf and remove the
dimmer unit from the airplane.
11-148. INSTALLATION
OF SOLID STATE DIMMER ASSEMBLY. (Serial Nos.
31-7512046 to 31-7812129.)
a.
Position dimmer unit on radio shelf.
b.
Secure dimmer unit to the radio shelf with appropriate screws.
c. Connect the electrical harness connector for the dimmer unit, from which the old
unit was previously removed.
d. Connect the electrical harness for the variable resistor to the variable resistor and
secure to overhead panel with appropriate nut.
e. Attach knob to variable resistor and check operation of dimmer assembly.
f.
Position radio shelf access panel and overhead royalite panel and secure with
appropriate screws.
11-149. REMOVAL OF SOLID STATE DIMMER. (Serial Nos. 31-7912001 and up.) The
dimmer unit is mounted on the upper bulkhead at Sta. 81.00 on the right forward side.
a.
Remove the screws securing the access panel between Sta. 59.00 and Sta. 81.00 on
the right side of the fuselage and remove panel.
b. Locate dimmer assembly on upper, forward bulkhead at Sta. 81.00 and disconnect
electrical connector.
c. Remove the four screws securing the dimmer assembly to the bulkhead.
d.
Remove the dimmer assembly from the airplane.
Reissued: 10/12/79
ELECTRICAL SYSTEM
4D22