TM 9-2320-260-20
Section III. PRINCIPLES OF OPERATION
I
1-16. GENERAL
This section explains how components of the 5-ton, M809 series vehicles work together. A functional
description of these components and their related parts will be covered in the following paragraphs. Elec-
trical wiring schematics shown are for reference only and are not to be used for troubleshooting. To find the
operation of a specific system or component, see the principles of operation reference index below.
I
PARA.
PAGE
TITLE
NO.
NO.
Control Systems Operation
Power Systems Operation
Electrical Systems Operation
Compressed Air and Air-Hydraulic Brake System Operation
Special Purpose Bodies Systems Operation
1-18. CONTROL SYSTEMS OPERATION
The control systems include those controls and their related parts that are essential to the operation of
the vehicle. These controls are common to all vehicles with the exception of transfer case power takeoff
controls. Each of these parts will be described as part of the following systems:
a. Starting System Operation (page 1-38).
b. Cold Starting System Operation (page 1-38).
c. Accelerator Controls System Operation (page 1-39).
d. Parking Brake System Operation (page 1-40).
e. Steering System Operation (page 1-41).
f. Clutch Control System Operation (page 1-43).
g. Transfer Case and Power Takeoff Control Systems Operation (page 1-44).
a. Starting System Operation.
The starting system will start the engine in all types of weather and has built-in protection that
prevents starter engagement once the engine has started. Major components of the starting system are:
A BATTERIES - Four 6TN batteries provide 24-volt power to energize starter motor and electrical
accessories.
B BATTERY SWITCH - Activates all electrical circuits except arctic heaters.
RUN, and START positions. Switch automatically returns from START to RUN when released,
D PROTECTIVE CONTROL BOX Prevents engagement of starter motor once engine is running.
E STARTER MOTOR - When energized, converts electrical energy to mechanical power as it
engages the flywheel to crank engine.
1-36
