* Mercedes-Benz Repair Manual: The most reliable source is a factory repair manual specific to your vehicle's year and model. These manuals often have detailed diagrams and instructions for belt replacement. You can find these manuals online (often as PDFs) from various sources, but be cautious of counterfeit versions. Genuine manuals are more expensive but provide the best information.
* Online Automotive Parts Websites: Many online parts retailers (like AutoZone, Advance Auto Parts, or others) allow you to look up parts diagrams for your specific vehicle. Search for your car's year, make, and model, then look for the "diagrams" or "schematics" section related to the engine. They may show the serpentine belt routing. Note that the quality of these diagrams can vary.
* Repair Manuals from Other Publishers: Companies like Haynes and Chilton publish repair manuals that are more affordable than factory manuals but may lack the detail or precision of factory documentation. Check their websites or your local auto parts store.
* YouTube Tutorials: Searching YouTube for "2003 Mercedes C320 serpentine belt replacement" will likely yield videos showing the belt routing. While helpful for visualization, always cross-reference with a diagram from a reputable source.
Important Note: Before attempting any repairs yourself, it's crucial to understand the process and have the correct tools. Incorrect belt routing can damage your engine. If you're unsure about any aspect of the replacement, it's best to have a qualified mechanic perform the work.
