To use any wiring diagram for your vehicle, you must be able to identify the components and types of system being used so that you will know if such automotive electrical diagram will work for you.

Tracing wiring diagram requires understanding the source of power and ground supplies including the ability to read color coding abbreviations for the wires and components. This, coupled with knowing the function of each component, will teach you how to trace the path of both power and ground supply. Once you grasp this, you should be able to read any wiring diagrams.

Most automotive wiring diagrams depict the power source usually on the top of the wiring diagram and the ground source at the bottom. The wires connect any components in between, which uses color coding. This coding makes tracing easy when testing different components at the same time. In the older times, wiring diagrams can be put in fewer pages of a book, which makes tracing very easy. Nowadays, because of the complex system being used, wiring diagrams are made to show individual system so they can be analyzed separately.

When tracing different system, you need to recognize the different circuit being used in your engine. This why wiring diagrams are composed of sub system of circuits working as a whole. Here are some typical electrical system (or circuits) used in a typical single modern day car:

# Alarm control circuit
# ABS circuit
# AC (and compressor) circuit
# Airbag circuit
# Charging (alternator) circuit

# Engine control (computer) circuit
# Heater (and blower) circuit
# Horn circuit
# Instrument panel circuit
# Lighting (both external and internal) circuit
# Ignition (distributor or non-distributor) circuit

# Power window circuit
# Power door (and trunk) circuit
# Radio and audio circuit
# Starting and Charging circuit
# Transmission (both automatic and manual) circuit
# Washer and wiper control circuit

When you look at this as a whole, it is very intimidating to fix any system when you consider the numerous circuits involved but if you attack it with one circuit at a time and use a wiring diagram, you should be able to handle it. So remember when you have any vehicle electrical wiring problem: find out first what symptoms is showing the system being used and then use the system wiring diagram to trace the fault. Example: you cannot fix your starting problem by checking your AC system. Only thru proper understanding of what system is actually at play that you will be able to trace it.