when i got problem in the
headlight for my cavalier, i find out how to troubleshoot this one. it says that i need to first see the factory diagram of the vehicle and multimeter. the diagram can be seen from gm factory service manual set. reason why you need the factory wiring diagram it is because the wires are all in bundles and wrapped up. Many wires are concealed and impossible to get to. Thus you can't follow a wire and see where it goes. The factory service manual, in addition to providing the schematic wiring diagrams for everything in the vehicle, will show locations of connectors and components, and will show which pin positions/wire colors are for what.