AUTO ELECTRICAL

Maintain Auto Electrical Systems

Module: RAE – 2

Overview

Familiarize the trainee with the set of the gap of the contact breaker points, the spark plugs, and adjust the engine timing. Trace and repair faults which may occur in the starting circuit, the ignition circuit, the charging circuit or the lighting circuit. Start the diesel engine when cold or hot.

Key and critical concepts you will learn

On completion of this module, the trainee must be able to do:

  • The spark plug gap, the contact breaker points gap and the timing must be set according to the specifications given in the workshop manual.
  • The correct methods must be used when tracing a fault in the electrical circuits.
  • Capacitors must be tested as prescribed.
  • Any broken or blown globes must be replaced with the correct types and sizes.
  • Blown fuses must be replaced with fuses of the correct size and current-carrying capacity.
  • Any componnts that are removed must be disassembled, repaired and assembled according to the workshop manual.
  • No nuts, bolts, studs or screws must be damaged or stripped when being removed or replaced.
  • Any faulty wires must be replaced with wires of the correct colour and size.
  • All the connections must be clean and tight.
  • The glow plugs of the diesel engine must be tested correctly, and the engine must start under cold and warm conditions.
  • Tools and Equipment must be used in a correct manner.

Whilst learning towards this outcome you are required to achieve the following:

  • A combined theory and practical test will be set at the end of the module and must be completed without using references.
  • A motor vehicle operates on two basic systems, namely, the electrical system and the mechanical system.  These systems are dependent on each other.  The engine is started by the battery which in turn must be charged by the generator or alternator which is driven by the engine.
  • The electrical system is divided into four parts which differ for the different makes of vehicles.  Each part is explained in this module.  They are:
    • Starting circuit
    • Ignition circuit
    • Charging circuit
    • Lighting circuit.

Tools, consumables, equipment and machinery required

  • A battery
  • Volt/amp/ohm Meter [Multimeter]
  • Thermometer
  • Battery Load Tester
  • Electronic battery Tester
  • Battery Charger
  • A motor vehicle. (Petrol and Diesel)
  • The relative workshop manual.
  • All the necessary tools and equipment.

Prerequisite modules

  • ST- Safety
  • LOP – Lockout procedure.
  • RAE – 1

INTRODUCTION TO THE ELECTRICAL SYSTEM OF A VEHICLE

The electrical system is divided into four parts which is different from different makes of vehicles.  Each part is explained in this module. They are:

Application

All vehicles must make use of the:

  • The electrical system that is divided into
    • Starting circuit
    • Ignition circuit
    • Charging circuit
    • Lighting circuit.

Additional resources & References.

  • A demonstration by a competent person for e.g. your Instructor/HRD Officer/ETDP
  • Workshop manual. [OEM “Original Equipment Manufacturer”] Specification and operational manual.

Maintain a Battery

Module: RAE – 1

Overview

Familiarize the trainee with the different types of batteries, their uses , their operation and enable him/her to identify the different types of batteries and their capacities, do pre-checks on a lead-acid cell battery, to connect batteries in series and parallel and to do a variety of different tests on a battery.

Key and critical concepts you will learn

On completion of this module, the trainee must be able to:

  • Determine the state of the battery.
  • Battery Visual inspection [water level; battery casing for cracks, battery soaked condition; condition of the poles etc.]
  • Battery polarity. [volt meter]
  • Battery total voltage.
  • SG [Specific Gravity] test with a Hydrometer or Refractometer test.
  • Battery Terminal/clamp resistance test.
  • Battery Parasitic drain
  • Battery load test           
  • Electronic Battery Test
  • Battery charge.
  • Battery jump starting

Whilst learning towards this outcome you are required to achieve the following:

  • A combined theory and practical test will be set at the end of the module and must be completed without using references.
  • There must not be any damages on the battery. [Wrong connections can cause an explosion that can be devastated].
  • There must not be any damage to any tools and equipment.
  • The specific gravity reading of the electrolyte must be given within the limits of ± 0,01 (10 gravity points) on the hydrometer scale with battery temperature that forms part of the calculation.
  • All the safety precautions must be applied when charging the battery.
  • If the battery in a sound condition, fully charged and ready for use.
  • The safety precautions taken when charging batteries with a battery charger in a specified battery charging room.
  • Interpretation of the information on the battery label.

Tools, consumables, equipment and machinery required

  • A battery
  • Volt/amp/ohm Meter [Multimeter]
  • Thermometer
  • A hydrometer/ Refractometer
  • Battery Load Tester
  • Jumping Cables
  • Electronic battery Tester
  • Battery Charger

Prerequisite modules

  • ST- Safety
  • LOP – Lockout procedure.

INTRODUCTION TO BATTERIES

  • DESCRIPTION:
    • A lead-acid storage battery is an electrochemical device that produces voltage and delivers electrical current. The battery is the primary “source” of electrical energy used in vehicles today. It’s important to remember that a battery does not store electricity, but rather stores a series of chemicals and metals like Lead, Zink or Nickel.
    • A chemical reaction taken place between the different metals and acid that produces an electrical pressure called voltage.
    • This electrochemical reaction changes chemical energy to electrical energy and is the basis for all batteries.
    • An electrical current will flow through a circuit, when positive and negative plates in the battery casing are connected in series that will form a [12V] circuit

Application

  • Batteries are an integrated part of all types and sizes of vehicles.
  • No vehicle can start or run without a battery.
  • The battery has several functions, for e.g. for starting process, supplying power to the ignition, lights, starter and a lot of other duties as you will learn in the Battery  Learning Material.

Additional resources & References.

  • A demonstration by a competent person for e.g. your instructor/HRD Officer/ETDP
  • Workshop manual. [OEM “Original Equipment Manufacturer”] Specification and operational manual.