BOLT 1D4585 - Caterpillar

Ignition systems can cause electrical shocks. Avoid contacting the ignition system components and wiring.Do not attempt to remove the valve covers when the engine is operating. The transformers are grounded to the valve covers. Personal injury or death may result and the ignition system will be damaged if the valve covers are removed during engine operation. The engine will not operate without the valve covers.When the ignition harness is reconnected, ensure that the Engine Control Switch (ECS) is in the STOP position or the OFF/RESET position so that the ignition system is immediately discharged.If the wiring harness is reconnected with the ECS in the AUTOMATIC position or the MANUAL START position, the storage capacitor of the ignition system may discharge. If the wiring harness is reconnected with the ECS in the AUTOMATIC position or the MANUAL START position, the storage capacitor of the ignition system may fire a spark plug. The spark plug will ignite any gas which is in the cylinder. The crankshaft can rotate and the crankshaft can be damaged. The driven equipment can also rotate and the driven equipment can also be damaged. Personal injury or damage to the equipment may be a result.Gas that has accumulated in the exhaust system may also be ignited.Magneto (If Equipped)
The storage capacitor in a breakerless magneto can be charged by turning the magneto by hand. The storage capacitor can be charged even when the wiring harness is disconnected from the magneto.Before connecting the wiring harness to a breakerless magneto, discharge the storage capacitor to the ground. Use the following procedure to discharge the storage capacitor:
Attach one end of a wire to the magneto housing.
Contact the other end of the wire to the connector pins for the wiring harness that is on the magneto. You will hear a “snap” when the storage capacitor discharges.
Ground all of the connector pins. This will ensure that no charge is in the magneto. Some breakerless magnetos have more than one storage capacitor.Turn the ignition switch to the OFF position before connecting the wiring harness. If the ignition switch is in the OFF position, the storage capacitor is immediately discharged to the ground when the wiring harness is connected to the magneto.Caterpillar Digital Ignition System (CDIS)
The Caterpillar Digital Ignition System (CDIS) replaces mechanical parts that are prone to wear. The system provides more precise control of ignition timing.The digital ignition system includes a timing disc, a speed sensor (timing), a timing control, and wiring harnesses. There is no magneto. The sensor monitors the rotation of the timing disc in order to sense a reference position of the crankshaft. The sensor sends a signal to the timing control for each cylinder. The timing control initiates the ignition by providing a pulse to the transformer of the proper cylinder.There are two options for providing the electrical power for the timing control:
The customer provides a source of 12 VDC or 24 VDC. (The customer can order a belt driven alternator and a battery from the factory.)
An alternator