Cessna 150M - Compass and Radio Dial Lighting; Control Wheel Map Light; Pitot Heater; Cigar Lighter

16-64. REMOVAL AND INSTALLATION. For re-
moval and installation of instrument and dome lights
refer to figure 16-8.
16-65. COMPASS AND RADIO DIAL LIGHTING.
16-66. DESCRIPTION. The compass and radio dial
lights are contained within the individual units. The
compass light is controlled by the instrument light
dimming rheostat located in the overhead console on
the 1969 models. Beginning with 1970 models the
instrument light dimming rheostat is located on the
instrument panel. The radio dial lights are control-
led by the radio dial light rheostat located on the in-
strument panel.
16-67. CONTROL WHEEL MAP LIGHT.
16
-68. DESCRIPTION. An optional control wheel
map light may be installed in the aircraft. The
map light is mounted on the underside of the con-
trol wheel and light intensity is controled by a
thumb operated rheostat. For dimming, the rheo-
stat should be turned clockwise.
Thru 1970 aircraft only, failure to observe
polarity shown on wiring diagram in Section
20, will result in immediate failure of the
transistor on the map light circuit board
assembly.
16-69. REMOVAL AND INSTALLATION (THRU 1970
MODELS). (Refer to figure 16-9).
a. For easy access to the map light assembly,
rotate the control wheel 90°.
b. Remove the four screws from the map light cir-
cuit board. The map light assembly will then be free
for removal from the control wheel.
c. Label the wires connecting to the map light cir-
cuit board assembly and remove the screws securing
the wires to the circuit board assembly.
d. To install the map light assembly, reverse this
procedure.
SHOP NOTES:
16-70. REMOVAL AND INSTALLATION (1971
MODELS AND ON).
(Refer to figure 16-9).
a. For easy access to the map light assembly, ro-
tate the control wheel 90°.
b. Remove the screws (9), spacers (8) and shield
(10) on 1972 Models and on.
c. Remove screws (7), inserts (11) and on 1972
Models and on, shield (10).
d. Label the map light assembly wires at the termi-
nal block, then remove the screws securing the wires
to the terminal block.
e. For reassembly, reverse this procedure.
16-71. PITOT HEATER.
16-72. DESCRIPTION. An electrical heater unit
may be installed in the pitot tube. The heater offsets
the posibility of ice formation on the pitot tube. The
heater is integrally mounted in the pitot tube and is
operated by a rocker switch on the instrument panel.
(Refer to figure 16-10).
16-73. CIGAR LIGHTER.
16-74. DESCRIPTION. Thru Aircraft Serials
15075564, F15001143, A1500480 and F A1500261 the
cigar lighter (located on the instrument panel) is
equipped with a thermal-actuated circuit breaker
which is attached to the rear of the cigar lighter.
The circuit breaker will open if the lighter becomes
jammed in the socket or held in position too long.
The circuit breaker may be reset by inserting a
small probe into the. 078 diameter hole in the back
of the circuit breaker and pushing lightly until a
click is heard.
Make sure master switch is "OFF" before
inserting probe into circuit breaker on
cigar lighter to reset.
Beginning with Aircraft Serials 15075565, F15001144,
A1500481
and F A1500262 a 9 amp inUne fuse is in-
stalled and replaces the circuit breaker to protect
the wire from the cigar lighter to the ammeter.
Change 2
16-27