Fig. 1: The Matco CM600 shows that the current through the fans is 4.1 amps on the current probe.
Fig. 2: The capture on the Vantage Pro shows that the current slowly ramped up during the first minute.
Fig. 3: Brushed DC motors are a dead short at rest, so it’s to be expected that the test light will illuminate.
Fig. 4: A Raytech infrared thermometer was used to see which fan was the hottest.
The Power Probe Hook is another tool for detecting circuit shorts. For information on this product, go to VehicleServicePros.com/10727929.