TROUBLESHOOTING THE HMMWV - OD1616 - LESSON 1/TASK 2
In order to effectively troubleshoot any system on any vehicle,
maintenance personnel must first have an understanding of the
components and operation of the system they are troubleshooting. The
purpose of the following paragraphs is to introduce the operation of
the HMMWV electrical system components.
The electrical system on any vehicle serve an indispensable
Without the electrical system, most vehicles could not be
It would be impossible to operate the vehicle at night
since there would be no external or internal lighting. Additionally,
there would be no way for the operator to monitor vehicle operation
such as speed, engine coolant, oil and a multitude of other items
that must be constantly checked to ensure correct vehicle operation.
In this lesson, the characteristics and operation of the HMMWV
electrical system will be discussed.
Electrical System Components. The HMMWV electrical system is a
24 volt system capable of submerged operation during fresh or
It provides for starting the vehicle, charging
the batteries, operating the controls, gages, and accessory items
peculiar to this vehicle.
In the paragraphs that follow, the components that comprise the
electrical system on the HMMWV will be discussed.
system on the HMMWV consists of 15 components as follows: batteries,
alternator, starter, wiring harness, protective control box, circuit
breakers, instruments, gages, indicators, lights, horn, windshield
(1) Batteries. Two 12 volt batteries are connected in series to
supply the 24 volt current required to start and operate the engine
The batteries are mounted in an enclosed compartment
under the right front crew seat.
They are secured by a hold down
The batteries are joined by a negative to positive jumper
The remaining negative terminal is connected to the vehicle
ground, while the other positive terminal is connected to the vehicle
The batteries supply the necessary power that is required