"Waterproof Cooling Fan" Failure Analysis: pick-up examination after maintenance personnel found the car radiator cooling fan deputy does not work, replace the rear sub-cooling fan test, the discovery of new cooling fan does not put the deputy low speed, only high speed, with the multi meter to measure the deputy "Waterproof Cooling Fan" low-speed circuits, found to have been disconnected. Maintenance personnel to replace the vice again after cooling fans, in order to avoid parts damage, do not rush to test, but in the dual temperature switch F18 at the jumper wire, so that the cooling fan at low speed, then find Vice "Waterproof Cooling Fan" appears on back of motor fire and immediately disconnect the jumper wire to make the cooling fan stops. Before the disintegration of the cooling fan replaced the deputy checked and found the series resistance of the motor has been burned, but the motor coil is intact.