Understand the Electrical Systems Check Engine Light
The electrical systems of vehicles, is in section. The front vehicle compartment, the engine compartment, the passenger compartment and the rear vehicle compartment. Connectors or the bulkhead connectors are used to interconnect the compartments. Always, have the repair manual with wiring diagrams and the vacuum system(this show where the vacuum hoses will go) for the vehicle (See how to understand wiring diagrams for car electronics).
SAFETYIf the battery needs to be disconnected, Always disconnects the battery ground(-) cable at the battery first. Be careful not to let the wrench touch the positive terminal(+). Locate the fuse panel.Anytime you work on the electrical systems of any vehicle. Always! Have the fuses you need for the car. for all parts of the vehicle. The electrical systems of vehicles, will sometimes use one or more fuses on some electrical systems(the stereo and the map lights can be on the same fuses).Before working on any vehicle, always set the parking brake. The vehicle may need to be put in neutral.
Tools that are good to have
- A repair manual with wiring diagrams and the vacuum system.* A diagnostic tool with the code book.* A digital multimeter( or a multimeter) for testing your electrical connections and looking for 12volt or the car ground.* a 12volt tester(test light) for looking for 12 volt lines.Some terms to learn:* Instrument panel or Instrument clusters: this is also known as the dash.* A/C control units: this is the heater control unit.* Instrument harness assembly: also know as the wire harness assembly.* Ground bolts: this bolt is the car grounding system.The front vehicle compartment:Head light, turn signal, and the horn is part of the front compartment. The units use a bulkhead connector and wiring harness, the wiring harness run though the front of the vehicle.The engine compartment is also in section:
The charging system:
The battery, the alternator, and the voltage regulator are the charging system. The alternator only works with the engine running, it takes the place of the battery and charges the battery as the engine is running. If the alternator goes bad, then everything runs of the battery. The voltage regulator acts like a switch, when the battery is completely charged, the voltage regulator will shut off the charge to the battery, and the vehicle will run off of the alternator. The voltage regulator can be part of the alternator.If the voltage regulator goes bad, it will not switch from the alternator to the battery, or it will not switch from the battery to the alternator.the vehicle's computer(module engine controller):
This unit controls, the ignition systems, the starting systems, the engine run systems, the safety sensor systems, the EGR, systems, the fuel injectors, the auto shut down systems, and the always dreaded check engine light (any of the systems can turn the dreaded check engine light on). This unit also has the diagnostic connector, which will let you talk to the vehicle's computer, with the uses of a diagnostic tool. You can now purchase an after-market diagnostic tool with the code book.The passenger compartment:This has the dash (an instrument panel), stereo, a/c and heater control, a windshield wiper switch, light switch for headlights, signal and side marker lights, the switch for an automatic power antenna( the automatic power antenna can be part of the front vehicle compartment or, the rear vehicle compartment).The rear vehicle compartment:
The rear lights, signal and side marker lights, wiring for a trailer.To understand the electrical systems of vehicles, can be easy. Always, have the repair manual with wiring diagrams and the vacuum system. You don't have to learn all the systems at one time, but some systems do affect other systems, so you may have to look at more then one system at the time. With the use of the diagnostic tool with the code book, the testing of the electrical systems as will as the engine is much easier.
