Piper Comanche PA-24 Service Manual page 830

12-1. Introduction.
This section of the manual is divided into two parts. The first part consists of the information necessary
to perform an operational check of the Piper Automatic Locator Transmitter along with the appropriate
removal and installation instruction to facilitate battery replacement. The second part consists of wiring
diagrams of the various configurations of avionics equipment installations.
12-2. Piper Automatic Locator Transmitter.
The automatic locator transmitter when installed is located under the access panel on the dorsal fin. This
unit operates on its own self-contained battery. Refer to latest amendment of AD 79-18-05. If the
transmitter has been used in an emergency situation or it has more than one hour of accumulated test
time, the battery must be replaced according to FAA regulations. To replace the battery back in the
transmitter, it is necessary to remove the unit from the airplane. The following instructions should be
used:
A. Remove the access panel located on the dorsal fin.
B. Remove the switch guard and set the ON/ARM/OFF switch to the OFF position.
C. Disconnect the whip antenna cable at the transmitter.
D. Remove the rear mounting bracket and remove the transmitter from the airplane.
E. Remove and keep the four screws securing the transmitter's plain end cap. Carefully remove the end
cap, trying not to damage the sealant.
F. Carefully withdraw the battery pack from the transmitter until the connector is exposed. Disconnect
the battery from the connector and discard the battery.
G. Before installing the new battery pack, check the replacement date. Transfer the self-sticking date
placard on the battery to the placard on the transmitter case.
H. Connect the new battery pack to the connector and carefully install it into the transmitter connector
end first. It may be necessary to rotate the battery slightly to get it seated properly in the transmitter
case.
I. Check the sealant on the end cap before putting it on the transmitter. If the sealant is damaged,
replace it with fresh silicone sealant, such as the type supplied by General Electric Co. Secure the
end cap to the transmitter with the four screws previously removed.
J. Install the assembled unit into the airplane and secure with aft mounting bracket. Connect the whip
antenna and set the ON/ARM/OFF switch to ARM.
NOTE: It may be advisable to test the unit operation before installing the access cover on the
dorsal fin. Refer to Paragraph 12-3 for test procedures.
K. Install the access cover and make an entry in the aircraft logbook.
04/01/09
PIPER COMANCHE SERVICE MANUAL
SECTION XII
ELECTRONICS
3H3
XII - ELECTRONICS