Take off the wire connections from the temperature switch in Toyota Avalon vehicles and connect the two ends together; if the fan stops this way, replace the temperature switch. Check for normal ohmmeter reading when the engine is cold (below 190 degrees F) and a missing reading when the engine heats above 208 degrees F with an ohmmeter testing the 1 Coolant Temperature switch. For this probe, the temperature switch #2 ought to work with the engine below 181 degrees F, and above 190 degrees F should make contact; fix the switch if it fails. If the fan motor won't run, start by examining the fuses and wiring connections. Then, connect a battery-powered fan to the motor using fuse-cutters, and test the motor separately - when the motor doesn't work, it needs replacement. When motor testing is complete and it won't work, check relays, wiring, and the cooling fan ECU. Locate a large circuit box near the driver's side engine compartment; check the number 1 cooling fan relay for good flow inside by connecting terminals 1 and 2 and terminals 3 and 4, but no power should flow between 3 and 4 with power applied between 1 and 2. To figure out which part needs repair, test the engine relay in four stages: battery voltage on 3 and 5, continuity on 1 and 2, 3 and 5 with continuity on 1 and 2 and no on 2 and 4, or 1 and 2 with continuity on 2 and 4 and none on 3 and 4. Take your car to a dealer or authorized mechanic for further checks if all test signal relays read normal. First, disconnect the battery cable and untwist the wiring connector where it connects to the fan motor. Then, unplug the cruise control actuator wire from the fan shroud if present. Next, unscrew the bolts that hold the fan/shroud to the radiator, grip the fan blades to unscrew the retaining piece, then detach the fan motor from the shroud with more bolts. The steps to install are simple: fit a fresh clip for the second fan motor and apply soapy water to the O-ring of a fresh switch before putting it in.