Wiring diagrams have gone through significant changes over the past decade and aftermarket wiring schematics have not evolved to represent those changes. Several aftermarket service information providers now have access to OE wiring diagrams. These diagrams include additional information and hotlinks designed to help the dealership technician efficiently diagnose electrical issues. This course guides technicians through the effective use of OE wiring schematics as a diagnostic tool. It is essential to understand how the problem circuit works, or does not work, on paper before one can accurately diagnose the problem on the vehicle. Planning your diagnostic strategy at your PC before diving under-the-hood or dash is the most effective way to solve circuit problems.