Section XI. MAINTENANCE OF CONTROLS AND INSTRUMENTS
d. Installation. Install three mounting nuts and
Drycleaning solvent, P-D-680, used to
lockwashers to install battery and generator in-
clean parts is potentially dangerous to
dicator in instrument panel.
personnel and property. Do not use near
4-46. Toggle Switches
open flame or excessive heat. Flash point
of solvent is 138°F.
a. General. The two toggle switches control the
front and rear floodlights. Before removing swit-
ches, check operation in ON and OFF positions by
This section contains information for organizational
observing operation of the floodlights. Before at-
maintenance of the controls and instruments of the
tributing a malfunction to a defective switch, make
sure that lamps are not burned out and that elec-
trical connections are correct.
Disconnect battery (+) cable from bat-
tery before disconnecting any wiring
(1) Refer to figure 4-31 for location of the front
and rear floodlight toggle switches.
(2) Tag and disconnect electrical connections.
4-44. Engine Hourmeter
(3) Remove two locknuts and remove switch
a Removal. Refer to figure 4-31 for location of
from instrument panel.
hourmeter. Tag and disconnect electrical lead.
c. Cleaning and Inspection.
Remove six nuts, six screws, and three lockwashers
attaching hour-meter to instrument panel and
Compressed air used for cleaning pur-
poses will not exceed 30 psi. Use only
with effective chip guarding and personal
b. Inspection and Testing.
protective equipment (goggles/shield,
(1) Inspect the hourmeter for broken glass.
Inspect the electrical wiring for cuts, breaks, and
(1) Clean toggle switches with an approved
cleaning solvent and dry thoroughly, or use low
(2) Connect hourmeter to a 24 volt power source
pressure compressed air.
and check for proper operation by checking in-
(2) Inspect switches for loose connections or
dicator above odometer wheels. Indicator should
broken hardware. Replace a defective switch.
revolve once per minute.
d . Installation. Mount toggle switch on in-
(3) Replace a defective hourmeter.
strument panel using two locknuts. Reconnect
c. Installation. Install hourmeter in instrument
panel using six screws, three lockwashers, and six
nuts. Connect electrical lead.
4-47. Panel Lights
4-45. Battery and Generator Indicator
a. Removal. Refer to figure 431 for location of
panel lights. Disconnect electrical connector and
a. Removal. Refer to figure 4-31 for location of
remove two mounting screws to remove panel lights
battery and generator indicator. Tag and disconnect
from instrument panel.
electrical connections. Remove three nuts and
b. Inspection. Inspect the panel lights for loose
Iockwashers and remove indicator from instrument
connections, defective wiring, and missing or
burned out light bulbs. Replace defective lights.
b. Testing Test the battery and generator in-
c. Installation. Use two screws to mount panel
dicator by connecting it to an external 24-volt power
light on instrument panel. Connect electrical con-
source along with another voltmeter of known
accuracy. Compare the readings of both meters to
determine the accuracy of the indicator. The in-
4-48. Starter and Horn Push Button Switches
dicator readings should correspond as follows: red
a. Testing. Test for a defective switch by
(lb), 18-22V; yellow, 22-26V; green, 26-30V; and
disconnecting leads from switch to horn or starter,
and connecting a test light between the switch
c. Inspection. Inspect the battery and generator
terminals. Push the button. If the test light does not
indicator for broken cover glass and loose electrical
light, the switch is defective.
connections. Replace a defective indicator.