First, take a look under the hood, see if you can find the fan wiring at the motor, and trace it back, see if there are any damaged wires. If so, see if the Ford dealer will do a recall repair on it. I don't know if it applies to the Zetec. There is a fan relay, and other components, a schematic from the Ford service CD or manuals will help. If the coolant temp sensor is bad the check engine light will be on. Does the fan run steady if you turn on the a/c,if it does, leave the a/c on, until you can solve the problem.
