[RugbyRef]

Originally Posted by patrickt

Your fan motor is an inductive load, not a resistive load. What that means is that, unlike a light bulb on a dimmer switch, it will draw more and more current as the resistance from a poor connection increases, because of heat and add to that the "load" of the heat on the fan blades that will also increase the amperage. So, on a cool day in your garage when you're testing it that fan might draw 10 amps using your inductive ammeter to measure it. But, when the under hood temperatures get really hot, and the wiring connections get really hot, and the air that the fan is trying to move gets really hot, and your voltage drops down, your inductive load will suck more juice, thus higher amperage levels. The only way you can be absolutely positively sure how much amperage that fan is drawing under load is to have a reliable inductive amp gauge on it and watch it when it's under a load that has blown the fuse in the past, or if you spring for a gauge that has high amp memory recall you can just check to see what the high number was. I've seen guys at my local club duct tape their iPhone under the hood to videotape a gauge during a really hot run, but a cheap bluetooth camera is probably a better idea.

Excellent information...thank you!