The availability of diagrams will depend on a few variables including the year of your vehicle and how much of the vehicle is factory original. For original equipment diagrams, check your local auto parts stores for repair books for your specific vehicle published by companies such as Chilton's or Haynes. You may also order or download many repair manuals and individual diagrams online.
http://www.wirediagram.com/honda.htm
glove boxAnswering
description of fuses
Answering "Where can you find an online diagram of the underhood fuse box on a 1999 Honda civic ex?"
To change the brake light bulb on a 1999 Honda Passport find the light housing located in the trunk. Find the plastic covers for the lights and remove them. Pull the bulbs out carefully and replace them.
When changing spark plugs for the first time, a diagram comes in handy. A spark plug wiring diagram for a 1999 Honda Prelude can be found in its maintenance manual.
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Advance Auto Parts and/or Auto Zone should have it for about $25.
buy a repair manual at any auto barts store there only around 20.00 dollars
honda power washer diagram
2003 honda rancher vaccume diagram
I've got an Accord, and under the hood is a label with "Vacuum Line Routing Diagram" printed on it. Start there first.