OEM Service Manuals are original equipment manufacturer repair manuals that are generally used by licensed technicians and mechanics to fix vehicles in their workshops. The OEM manuals contain every single repair information in a detailed step-by-step format so that anyone can efficiently fix any issue. Apart from that the manuals even include wiring diagrams pdf and troubleshooting guides for various brands and models which help car owners get the visual representation of the complex electrical system of their vehicle.