PicoScope analysis of ATV cooling fans #1428

Cooling fan failure on ATVs is a major problem, often caused by water ingress damaging the electric motor. Quite often the failure is sudden and without warning often leaving the ride either stranded or risking serious engine damage by continued riding to get home. I was toying with the idea of measuring the amperage draw of the motors, knowing this would change should there be damaged commutator segments (high resistance). Comparing the reading of a used fan to that of a known good could give us a heads up that the fan is not operating as well as it should be, indicating the possibility of water ingress.... So, with a new PicoScope, some screen capture software & a handful of second hand cooling fans plus a brand new one, we get to compare the readings to see if I was right.... Now I'm no electrical engineer so if anyone what's to add to the analysis please feel free to add to the comments, though try keep the terminology you use relatively basic so we can understand what you are saying! Andy Mechanic