Car Blower Not Working on All Settings – What's the Reason?

The blower in your car may fail on all settings because of the blower motor failure, fan speed switch malfunction, climate control sensors problem, fuse issues, wiring problems, or battery/alternator issues. Also, your vehicle may have gone to the limp mode and turned off all the unnecessary parts including the blower.

Electrical equipment problems highlights

• Level of urgency:low
• DIY inspection:possible
• DIY repairs:possible but complicated
• Can you drive?yes
• Price of repairs:$150 - $350
• Ifignored:problems may develop and escalate
• Ways to fix:diagnose and replace the broken parts, try resetting the affected units

1. Blower motor death - one of the worst things

The blower motor is driving the fan that sends some air to the interior of your vehicle. It's usually located under the glovebox but you may want to check this in the driver's manual for your vehicle.

The failing blower motor is bad news because even taking it off the car is sometimes a huge problem. In some cases, mechanics will need to take apart half of the front panel to get to this motor.

But you may try to test it:

• find a source of energy with 12V (a car battery will be a great option);
• go under the glovebox and locate the blower motor;
• you will see the wiring that connects this motor to the system in your car;
• find a socket and disconnect it;
• think how you can connect the socket to the 12V battery to jump-start the blower motor;
• connect your 12V battery to the motor and see if it actually works;
• if it doesn't work, you've just found the problem;
• if it works, connect it back to the car wiring and keep reading to find the actual problem.

This way, you may check if the blower motor is still alive. This is the most problematic issue because of the complicated replacement procedure. But this is also the most common reason why your blower doesn't work on all settings.

The reason for the dead blower motor is usually water damage or voltage issues. It may have burnt because of the voltage spikes your alternator produced. In most cases, though, it's all about water issues.

2. Check the fuses

Before you do any other things, just check the corresponding fuse. You may find fuse maps on the plastic covers of fuse boxes in your car. Also, some fuse maps may be available in the driver's manual or in specialized forums.

Locate the needed fuse, take it out, and look at it. Even if it looks OK, take another fuse with the same amperage and insert it into the socket. You may take just some other fuse in the same fuse box to just check the blower motor. If after fuse replacement the blower motor starts working, congratulations, you've located the problem.

After that, you just need to buy the needed type of fuse and insert it into the fuse box. This is the cheapest and the fastest repair of the malfunctioning blower in your car. So, start with this!

3. Wiring problems and solutions

Unfortunately, here I won't come up with any DIY methods because I strongly recommend you avoid getting your hands on the wiring in your car unless you have the proper experience. Wiring problems are not really common but they are worth checking up on if you still couldn't locate the issue.

To check the wiring, find a specialist who can do this for you. The checkup will take some time because the mechanic will need to get to the needed wires and use some equipment to check their integrity.

Wiring and connection problems are just a usual thing for vehicles that have gone through water damage like floods or just spilled coffee.

4. Fan speed switch problems

All cars have a certain switch that allows you to control the fan speed and the intensity of airflow in the interior of your vehicle. This is an electric switch that is used to switch the fan on and to set a certain speed of the fan to control the airflow.

The switch may go bad and fail to turn on the fan. It may work in some settings while failing to work in others. But, in most cases, it will just fail to work at all.

To check the switch, you will probably need another switch, maybe you even can get a used one from a scrapyard. Take off the old switch and connect the new one instead. Turn the ignition on and try to turn on the blower. Is it working now? You may install the used switch that you bought or buy the new one and solve the problem.

Still not working? My goodness! Let's continue then...

5. Climate control sensors issues

If your blower is not working when you turn on the climate control, some sensors may just be broken or disconnected. Check this by turning the climate system to manual mode. Turn off the climate control, turn on the fan, and see if the blower is working this way.

If not, most likely, the climate control sensors are not the reason for your problem. If it works in manual mode, you will need a proper inspection of the climate control electronics to locate and repair the actual reason for this issue.

6. Battery or alternator problems

One more thing that can rarely cause this problem is a dying battery or a faulty alternator. Your blower is basically a piece of electric equipment that will work properly when supplied with the needed voltage. If the current is absent or the voltage is too low or too high, the blower will not work at all or will work with some problems.

To check this, you may use the same place where you were checking the condition of the blower motor. Use the multimeter to measure the voltage in the wiring that connects the blower motor to the system. If it's more than 14V or less than 10V, the problem should be with the electricity system.

When the engine is off, the battery supplies everything with the needed power. When the engine is on, this task goes to the alternator. So, the easy check: try to turn your blower on when the engine is off but the ignition (or accessory mode) is on. Also, try turning the blower on when the engine is on. This way, you may locate the problem and then inspect the battery or the alternator depending on the results of your investigation.

Although this is a rare problem, it's worth checking up if you still couldn't locate the issue.

7. The vehicle is in the limp mode

I've seen vehicle owners struggling to get at least some parts of their vehicles to work properly. Music is glitching, error messages are popping up, the blower is not blowing, etc. If this is the case, you should check whether your vehicle went to the limp mode.

This happens when the ECU registers a serious problem with the engine or transmission. Different types of issues may trigger the limp mode. Also, the engine power will be reduced. The majority of cars will show you on the dahs that the vehicle is in limp mode. But some older models will not.

Checking this is possible with a code scanner. The best strategy, in this case, is to let a professional mechanic check the vehicle and see why the limp mode was activated. If the limp mode is the reason for the blower malfunction, there is actually no problem with the blower itself. You need to find and solve the initial problem with the engine or other important units in the vehicle.

What to do if nothing of the above-mentioned things works?

If you still can't understand the reason for the problem in your vehicle and the blower still doesn't work, you should let a professional mechanic inspect the car and find the problem. You may have overlooked something or you may not have had the needed equipment to check a certain potential reason for the problem.

I can also tell you that the most common reason is still the blower motor itself. Inspecting its condition is not really easy. Sometimes, you will struggle to even locate it or find the electrical connection that you need to check.

I also recommend taking all modern vehicles (younger than 5 years) to the dealerships. Mechanics there are trained to solve issues like that and will most likely spend less time on inspections. Hence, you will spend less money for finding the problem.

If you need to replace the blower motor, better buy the OEM one. Otherwise, the aftermarket blower motor may fail in a month or two and you will have to repeat the whole procedure and pay for labor once again.