C-15, C-16, and C-18 Engines Caterpillar

Most of the tests of the electrical system can be done on the engine. The wiring insulation must be in good condition. The wire and cable connections must be clean. The wire and cable connections must also be tight. The battery must be fully charged. If the on-engine test shows a defect in a component, remove the component for more testing.

The starting system consists of the following four components:

• Keyswitch

• Start relay

• Starting motor solenoid

• Starting motor

Trouble with the starting system could be caused by the battery or by charging system problems. If the starting system is suspect, refer to Service Manual, SENR3581, "37-MT, 41-MT & 42-MT Series Starting Motors" or refer to Service Manual, SENR3860, "50-MT Series Starting Motors". These publications contain troubleshooting for the starting system, test procedures, and specifications.