To test the fan motor, unplug the electrical connector at the motor and use jumper wires to connect the fan directly to the battery; if the fan still doesn't work, replace the motor. If the motor tests OK, the fault lies in the coolant temperature switch, the relay, or the wiring connecting the components, so carefully check all wiring and connections. If no obvious problems are found, further diagnosis should be done by a dealer service department or a repair shop. Disconnect the negative battery cable from the battery, ensuring that on models equipped with the Delco Loc II audio system, the lockout feature is turned off before disconnecting the battery. Remove the air cleaner assembly, insert a small screwdriver into the connector to lift the lock tab and unplug the fan wire harness, then unbolt the fan assembly by removing the four cooling fan retaining bolts and carefully lift it out of the engine compartment. To detach the fan from the motor, remove the motor shaft nut, noting the left-hand threads, and to remove the fan motor from the bracket, remove the mounting bolts or nuts. Installation is the reverse of removal.