Piper Navajo PA-31 Service Manual page 771

PIPER NAVAJO SERVICE MANUAL
11-141. INSTALLATION OF ANTI-COLLISION - FIN TIP.
a. Install socket assembly on fin tip and secure with appropriate screws, placing ground wire on the
forward screw and securing.
b. Reconnect the electrical connector to the light assembly.
c. Install fin tip on fin and secure with appropriate screws.
11-142. REMOVAL OF ANTI-COLLISION FLASHER. The flasher unit is located on the aft side of the
bulkhead at Sta. 296 on the left side of the aircraft.
a.
To gain access to the flasher. remove the screws securing the access panel to the rear baggage
compartment and remove panel.
b. Locate flasher and disconnect the electrical connector (BLINK) from the unit.
c. Remove the two screws securing the flasher unit to the bulkhead.
d. Remove the flasher unit.
11-143. INSTALLATION OF ANTI-COLLISION
FLASHER.
a. Secure flasher unit to bulkhead with two screws previously removed.
b. Reconnect the electrical connector.
c.
Install aft panel in rear baggage compartment and secure with appropriate screws.
11-144. INSTRUMENT
LIGHTS. The switch and circuit breaker panels are of the electro-luminescent
type. The individual instruments on the instrument panel are lighted by bolt lights. The light intensity of the
electro-luminescent panels and bolt lights are controlled by solid state dimmer. If necessary to remove the
solid state dimmer, use the following instructions.
11-145. DESCRIPTION
OF OPERATION
FOR THE SOLID STATE DIMMER
ASSEMBLY The
potentiometer(s) controlling the flight panel lighting is/are connected to a Solid State Dimmer assembly.
When the potentiometer's control knob is turned on the lighting intensity is very dim. Lighting intensity
increases with a clockwise rotation of the potentiometer's control knob until it reaches its brightest intensity.
At this point the knob will no longer turn clockwise. Reversal of knob movement will allow the lighting
intensity to be adjusted to a suitable level. When the lighting intensity is turned to a lower setting, the solid
state dimmer serves as a release for excess heat.
11-146. TROUBLESHOOTING
PROCEDURE FOR THE SOLID STATE DIMMER ASSEMBLY.
When troubleshooting the solid state dimmer assembly, utilize the appropriate schematic (Panel Lights)
in this manual. It must first be determined if the trouble is a defective dimmer assembly or a shorted or open
connection in the wiring for the unit. Verify that the wiring is not shorted as this could have caused the dimmer
to burn out. Verify that the proper voltage exists at the circuit breaker and at the dimmer connector. To check
voltage at dimmer assembly connector. gain access to dimmer assembly as described in removal of solid state
dimmer and measure voltage at connector. If voltage is present, the solid state dimmer assembly may be
defective. If the wiring is not shorted or opened, replace the solid state dimmer assembly.
Revised: 1/29/82
ELECTRICAL SYSTEM
4D21