Years ago, when trying out for an outfield position on a pony league team, I was chasing after a high fly ball. Since the infielder had run back to catch it, I called him off screaming, “I got it, I got it!”
The customer’s agitation increased as he watched Vince’s finger trace the path of the circuit. Finally he asked why Vince was spending time looking in a book instead of simply fixing the car.
Why wander into an unknown electrical problem without an electrical schematic diagram? Think of a schematic as a tour guide which will deliver you to a successful repair with as little lost motion as possible.