burned fuses, or corroded battery terminals, a technical manual may not be required; however, for more complex, electrical systems, it is a necessity. Use EXTREME CAUTION when working around any electrical system on any CESE. Crossing wires or flashing wires to ground-to check for current may all lead to major damage, costly repairs, or personnel injury.

When you troubleshoot any system, have a set plan to approach the problem. Keep it simple; eliminate easy items, such as a dead battery, burned out light bulbs, blown fuses, and so forth. Once the simple fixes are out of the way, use your own set plan to solve the problem. One plan that may be of help to you is the following:

1. Know the machine and find and read the technical manual to understand the problem.

2. List all the possibilities of the fault.

3. When possible, speak to the operator and find out how the unit malfunctioned in a working situation.

4. Operate and inspect the machine yourself.

5. Systematically test individual circuits until the problem is found.

6. Test your findings.

7. Repair CESE and return it to service.

As an afterthought, once a unit of CESE is repaired and returned to dispatch, discuss your findings with other CMs in the shop. Do not play, I've Got a Secret with repair information.

Before proceeding with any electrical tests on automotive or construction equipment, check the power source (battery) and its connections first. A dead or poorly grounded battery may not light lights, work solenoids, or run motors. On the other hand, a poorly grounded battery may work many of the vehicle components, but not certain electronic circuits. Remember to check the battery and its connections first; for the remainder of this chapter, before any troubleshooting procedures are explained, it will be assumed that you have done so.

HEADLIGHTS

The most common problem in headlight systems is burned out light bulbs. This may be eliminated simply by replacing the bulbs. If the head lamp still does not work, remove the lamp from the socket and check the leads on the multiwire connector to the lamp with a 12/24 volt test lamp or a volt/ohmmeter (multimeter) (fig. 4-43). Make sure the headlight switch is turned on.

Figure 4-43.-Troubleshooting headlight wiring (typical military system).