(2) Lift the radiator (7) up into position, making certain that a new rebound unit (11) is placed between the
radiator mounting angle and the compressor frame.
(3) Insert the hex head bolts (12) up through the frame, rebound unit, and mounting angle, and install the
remaining rebound units (11), the plain washers (10) and castellated nuts (9).
(4) Reinstall the fan guard (par. 87b).
(5) Reconnect the coolant hoses to the radiator inlet and outlet openings (par. 86).
(6) Reinstall the housing components (par. 130).
(7) Reinstall the radiator shutter assembly (par. 84b).
(8) Close the shutoff cock and fill the cooling system with 10 gallons of antifreeze solution and 6 1/2 gallons
water. Add an approved rust inhibitor.
(9) When assembling the radiator rebound units (11), the nuts (9) should be drawn down finger tight and turned
one full turn with a wrench when the radiator is full of coolant. Install the cotter pins (8).
Section VIII. ELECTRICAL SYSTEM
89. Description
a. General. Three basic electrical circuits that are incorporated into the engine-air compressor are the ignition circuit,
the starting circuit, and the generating circuit. All three circuits are provided with radio interference suppression equipment
and are treated for moisture and fungus-proof resistance.
b. Ignition Circuit. The ignition circuit includes the ignition switch, distributor and coil, spark plugs, and all wiring and
cables which interconnect those components. Each of these parts must be functioning properly to complete the ignition
circuit. The 24-volt distributor and coil are assembled into one housing to increase radio interference suppression. It is
mounted on the crankcase cover and is driven by the accessory drive gear.
c. Starting Circuit. The starting circuit supplies the power to crank the engine and includes the starting motor,
magnetic switch, starting button, batteries, and all interconnecting cables and wiring. The 24-volt starting motor is
equipped with a Bendix drive which automatically meshes the drive pinion with the engine flywheel for starting and
disengages after the engine has been started. The 24-volt magnetic switch is mounted on the battery box and is used to
close the circuit between the batteries and the starting motor. When the starting button on the instrument
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