I’ve worked with technicians who had whole tool box drawers filled with specially modified wrenches and other hand-made problem solving tools. Somewhere along the way, most of us have had to creatively bend, spindle, or mutilate our tools to finish some particularly frustrating job.

This article will show you how an automotive computer flips the switches to turn different output circuits either “on” or “off.” We’ll also discuss ways to protect sensitive computer output circuits from death and destruction.