Ways to Check Your Volkswagen Jetta Auxiliary Fan Assembly for Possible Problems
As a supporting component to the other car parts, the Volkswagen Jetta auxiliary fan assembly is a dual-purpose component that functions depending on its speed. At low speed, it cools the AC condenser when it is overworked or when it has reached a certain temperature. Then, when the engine needs to be cooled down, that's when the auxiliary fan notches up to higher speeds to cool down the radiator. Because of its functions, you can notice when this component starts to fail. When you notice that there is something wrong with the air conditioner, the engine, or the radiator, then it's time for troubleshooting. Here are some ways to diagnose your car's auxiliary fan assembly.
The first step to finding a problem with your auxiliary fan assembly is to observe the component and its connections. First, make sure that the fan blades are clear of all obstacles and can turn freely. The auxiliary fan assembly's position tends to make them subject to debris collection. Also, check the 10-amp fuse marked "air cond" as well as the one marked "rad fan" on the relay box cover. If one of them is blown, replace it with a new fuse immediately.
When doing a troubleshooting on the auxiliary fan assembly, you should not only focus on the component itself-it's highly recommended that you check the whole system as well. Remember that if one part is going faulty, it could be caused by another component. You can use a thin piece of cardboard in order to force the air conditioning system to behave under the non-speed sensitive conditions. Slide an unfolded cereal box down between the radiator and A/C condenser-found just in front of the radiator fan-to block airflow from the engine fan or puller. If you are doing a system check on a hot day, partially obstructing airflow will do the trick. On the other hand, if it's on a cool day or if your system is still efficient, then it is more necessary to remove the two top radiator brackets. This will completely block the airflow across the entire radiator.
This is quite a common procedure especially if you have been modifying your car. When doing a circuit test, it is important that you have a visual reference specific to your car's model year. To test an auxiliary fan motor, unplug the electrical connector attached to that component. Then, use fused jumper wires to connect the battery power and ground directly to the fan. If the auxiliary fan does not operate, then you have to replace the motor.