Don't feel bad if you get discouraged while working with automotive electrical wiring diagrams.  Making heads or tails of it can be difficult, especially if the diagrams span multiple pages. Here's a simple tip that can save you a lot of time and frustration when diagnosing an electrical problem.

Highlighting electrical diagram

Photo credit (derivative work) - http://www.flickr.com/photos/katerha/

If the diagram you are working with is difficult to follow, simply grab a few highlighter markers and trace each individual leg of the circuit with different colors.   Once the individual circuits are identified, most of the diagram can be ignored and you can easily follow the relevant parts of the diagram.