Man, I've been there. That Phoenix dispatcher did you a favor honestly. I used to quote razor thin on purpose to win loads and then ate it hard when a driver's ELD went sideways outside Amarillo. Now I add 6 to 8 percent on anything touching a holiday or a Monday pickup, and I bake in a flat 50 bucks for "weather flex" on cross country runs. It costs me some jobs but the ones I get actually stick. The trick is to not show your whole math on the sheet, just leave a line that says "contingency" so they know it's not fluff.

Man, that thermistor thing hits close to home. Last month I had a Samsung that kept throwing a defrost error and I spent like three hours tracing the heater circuit, checking the bimetal, even pulled the evap cover off twice. Turns out the door switch was flaky, and when the door was closed just right it would short and kill power to the defrost sensor for a split second. Fridge was cold the whole time, so I never even thought to check the door. Had to wait for the customer's kid to come home and slam the door for me to finally catch it on my meter. Learned the hard way that codes are just a starting point, not a map.