why ? if you remove the wires attached to sensor side of the radiator,with ignition turned on bridge wires together fan MUST WORK as long as it does this its the only test of the fan motor required these fans are NOT designed for continuous operation if on reattaching the wires to fan and running the car up and above normal temp the fan WILL KICK IN JUST BEFORE THE RED at this point providing the fan can bring the temp DOWN system ok its when the fan don't work you in the deep mire stuff
wirecutterman, February 2008