WHEEL GP-IDLER 2805030 - Caterpillar

When boost starting an engine, the instructions in Systems Operation, "Engine Starting" should be followed in order to properly start the engine.This engine may be equipped with a 12 volt starting system or a 24 volt starting system. Only equal voltage for boost starting should be used. The use of a higher voltage will damage the electrical system.The Electronic Control Module (ECM) must be disconnected at the "J1/P1" and "J2/P2" locations before welding on the vehicle.
The engine has several input components which are electronic. These components require an operating voltage.Unlike many electronic systems of the past, this engine is tolerant to common external sources of electrical noise. Buzzers that use electrical energy can cause disruptions in the power supply. If buzzers are used anywhere on the machine, the engine electronics should be powered directly from the battery system through a dedicated relay. The engine electronics should not be powered through a common power source with other activities that are related to the keyswitch.Engine Electrical System
The electrical system has the following separate circuits:
Charging
Starting (If equipped)
Accessories with low amperageSome of the electrical system components are used in more than one circuit. The following components are common in more than one circuit:
Battery or batteries
Circuit breakers
Battery cables
AmmeterThe charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output in order to keep the battery at full charge.The starting circuit is activated only when the start switch is activated.The accessory circuit with the low amperage and the charging circuit are connected through the ammeter. The starting circuit is not connected through the ammeter.Charging System Components
Alternator
The alternator is driven by a belt from the crankshaft pulley. This alternator is a three-phase, self-rectifying charging unit, and the regulator is part of the alternator.The alternator design has no need for slip rings and the only part that has movement is the rotor assembly. All conductors that carry current are stationary. The following conductors are in the circuit:
Field winding
Stator windings
Six rectifying diodes
Regulator circuit componentsThe rotor assembly has many magnetic poles that look like fingers with air space between each of the opposite poles. The poles have residual magnetism. The residual magnetism produces a small magnetic field between the poles. As the rotor assembly begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced. The AC current is produced in the stator windings from the small magnetic field. The AC current is changed to direct current (DC) when the AC current passes through the diodes of the rectifier bridge. The current is used for the following applications:
Charging the battery
Supplying the accessory circuit that has the low amperage
Strengthening the magnetic fieldThe first two applications use the majority of the current. As the DC current increases through the field windings, the strength of the magnetic field is increased. As the magnetic field becomes stronger, more AC current is produced in the stator windings.