A customer's homemade part diagram saved a whole repair visit
Last Tuesday I went to fix a fridge that was tripping the breaker in a house near Tacoma. The owner, a retired electrician, handed me a hand-drawn wiring map he'd made after watching a YouTube video. Every wire, every terminal, even the voltage readings he got with his own meter, all labeled in pencil. His diagram pointed me straight to a short in the defrost heater that I would've spent an hour hunting. I just asked him if he'd ever considered selling those sketches, because that thing beat any schematic I've seen. Has anyone else had a customer hand you something that ended up being oddly useful?