wiring diagram explanation

until now, i guess i have enough knowledge to read wiring diagram after doing so many practice. so i think it is a good idea to sum up the way how i manage to read the wiring diagram for engine EFI system.
first of all, you have to find the engine information which normally can be found in the engine bay with a metal plate with engine information on it. or you can find the engine modle from the ECU which normally has the engine medle printed on it. once you have the information, then you can download the wiring diagram for the engine you choose to work on. the wiring diagram pakage includings all information you are gonna need. but also including the diagram for other engine modles, for example for the project we are doing, the wiring diagram pakage has information on left-hand-drive modles and aslo have the wiring diagram for 4E-FE ( for the project we only need 4A-FE). once you get right diagram you can continue to do the next step

from the  wiring diagram pakage wihch is for 4E-FE

from the  wiring diagram pakage wihch is left-hand-drive

for righ-hand drive which is the right one for the project

for 4A-FE which is the right one for the project

if you are familiar with a map, then it is basically the same principle.  all componnets are marked. since one paper can not show them all, you will notice they are seperated to different sections, put all these sections together you will have the whole picture. bear this in mind, one you find the power source which is normally the battery, then the conduct which is the wire, the last will be the componnet. all the wires in a car are  the same with the wiring diagram. and aslo the location of the components are indicated.