Cause of Car Heater Fan Not Working

If you are on a mission to fathom the reason behind your car heater fan not working, you have landed on the right page. Here I provide you with clues that might help you figure out what's causing the heater fan breakdown.
WheelZine Staff
As winter rolls in, one car part whose working becomes increasingly important is the internal heater. With the car heater functioning smoothly, rides through chilling weather are possible. There are a lot of things that may go wrong with the heater assembly, which you may need to look into, before the onset of winter. Many drivers often report the problem of car heater fan failure, which renders the entire heating system useless. If you find yourself in similar circumstances, help is on the way in the form of this WheelZine article, which will help you diagnose the root cause of the problem. In the following lines, I have outlined the prime causes of car heater fan failure.
About Car Heater Fans
A bit of background on the working of car heater fans will be helpful in diagnosing the source of the problem. The heated air circulated through vents into car interiors is directed by the heater fan. Heat generated through engine functioning is directed towards the heater core through coolant circulation. The core heats up and warms up air around it through convection. This warm air is blown into the vents by means of a fan, that is powered by a motor.
Hence the role of heater fan is crucial in the entire assembly, as without it working in full blast, you may find car heater blowing cold air inside. Fan failure is one of the most common causes of car heater failure. The fan is powered by a motor and derives power which is routed via fuses installed in the dashboard. In cars with ACCS (Automatic Climate Control System) installed inside, the heater operation and therefore the fan speed is automatically changed according to the interior temperature. With that background, we are ready to identify the prime causes which may lead to fan failure.
Prime Causes of Care Heater Fan Failure
Any of the supportive systems which influence the working of a fan, may cause its failure. Here are the most common causes.
ACCS (Automatic Climate Control System) Problem
With the functioning of blower motor and therefore the fan being handled by automatic climate control system, a failure in that system will directly affect it. An electronic circuit problem in ACCS, thermostat issues or loose wiring in circuitry may cause the fan to stop functioning. Fixing up the ACCS might solve the problem.
Dysfunctional Motor
The motive force for fan functioning is provided by the motor attached to it. A motor failure will obviously may cause the fan failure, causing an overall car heater failure. Fixing the motor should solve the problem in this case.
Blown Fuse or Loose Wiring
All power to every one of the electrical working parts of the car is supplied via fuses. A blown fuse might just be the reason your car heater fan is not working. Check for blown fuses and replace them to restore normal functionality. A problem with the switch which turns the fan on or off, might also be the source of the problem. So it's advisable that you get the switch checked too. If you find the fan working intermittently, one reason behind its erratic behavior might be loose wiring. Get the whole fan circuitry checked for loose wiring problems to rectify the error. Also a faulty alternator could make the blower motor stop working, leading to fan failure, when the blower motor stops is rendered dysfunctional.
Hope this article helps you in figuring out the reason behind car heater fan failure. If you find none of the above listed causes to be the culprit, it's time you called in car repair professionals and let them handle the job. Unless you get the problem fixed before winter sets in, your car is going to be grounded throughout the season! Ergo, you should get the care repair job done as soon as possible. Hopefully the pointers provided above will guide you in the right direction.