Common reasons for this to happen:
- Blown fuse: Like many electrical units in your car, the ventilation system relies on a fuse for overcurrent protection. If the ventilation system’s fuse blows, then the circuit will stop working, and there will be no power for the vents.
- Bad relay: A bad relay can also be responsible. A relay is a small current that controls a larger current. In this case, the relay takes a small electrical current and uses it to control the larger current that the ventilation system requires. When the relay stops working, the vents no longer receive the power they need to operate.
- Nonfunctioning or damaged blower motor: A blower motor is the motor that sends the air through the vents in your car. It is very similar to the motor that you’ll find on a leaf blower or a home fan. Blower motors can die or be damaged, which will slow or stop the power of your ventilation system.
- Blower resistor malfunction: The blower motor depends on resistors to control the speed at which air flows through your vehicle’s vents. A resistor essentially limits the output of the blower motor so that you only get as much air as you asked for.
- Clogged air intake: It’s also possible for an air intake to get clogged. Your car has two kinds of air intakes: fresh (air from outside of the vehicle) and recirculated (air from inside the vehicle). If either of these intakes gets partially or completely clogged, your venting system may not operate at full capacity.
- Broken hose: There are numerous hoses required to make a ventilation system work. Any leaks, clogs, or insecure attachments among these hoses can alter the ability of your vents to function properly.
What to expect:
A top-rated mobile mechanic will come to your home or office to inspect your ventilation system. Often they will check the fuse and relay first, and then attempt to run the fan to see what is and is not working, before exploring the system in more depth.
After the inspection, the mechanic will provide a detailed report that describes the source and cause of the issue, along with the scope and cost of the necessary repairs.
How important is this service?
You’re unlikely to do further damage to your vehicle by driving it when the vents aren’t working. The ventilation system is primarily for driver and passenger comfort, but it remains an important system within the vehicle, so issues with it warrant an inspection.