It's responsible for pushing air into the cabin through the vents. It's controlled by the fan control switch and blower motor relay, which are responsible for managing the amount of voltage the blower motor receives, allowing it to function at different speeds.
You need to use a multimeter and check for continuity from end to end of each fuse. If you have continuity, it's good. If it's open/no continuity, it's bad.
First see if a new fuse blows with the blower unplugged. If it does then there is a short between the fuse and the blower and the wire harness will need to be inspected to see where the short is. If the fuse does not blow with the motor unplugged the motor is shorted and needs to be replaced.
The blower motor turns the blower fan, which forces air through the heating, ventilation, and air conditioning (HVAC) system and out of the car's vents. Blower motors can operate at low, medium, medium-high, and high speeds. The symptoms of a bad blower motor are abnormal noises and weak or no airflow.
Blower Motor Resistor Test
Typically, if the fan will work on some speeds but not on others, the resistor is suspect. Okay, let's say there's no melting going on, but your fan doesn't work on all speeds. Typically, if the fan will work on some speeds but not on others, the resistor is suspect.
On some platforms, a faulty blower motor relay will cause the blower not to work at all, which means there will be no airflow from the A/C. On others, the blower won't work on “high blow” but all the other speeds will work. The blower motor relay fails because it regularly deals with high current loads.
The blower motor can indeed function without the resistor. As we know, the resistor is responsible for controlling the blower motor's speed by regulating the voltage supplied to it. It will turn out that without the resistor, the blower motor may run at maximum speed or not function as expected.
The traditional blower motor resistor is connected to ground, and wired in series with the blower motor assembly. Blower motor resistors have several resistors with different resistances. This controls the current that runs through the blower motor.
Blower motor is fuse 35 and is a 40 amp. You could test them with a meter or visually look to see if they're blown, then take it to a shop if they blow after replacing them.
On occasion though, the current may be too much for even the fuse causing it to blow. A fuse may have blown in your vehicle if you are struggling to start your vehicle, are no longer able to operate your headlights, windshield wipers, interior lights, radio, or other electrical components.
Strange Rattling, Clanking, or Screeching
One of the first signs you may notice when there's an issue with the blower motor is a strange noise coming from the indoor unit or air handler.
Intermittent Operation
When this happens, there's usually something wrong with either the blower motor itself or with another part of your furnace that controls it. Problems include dirty filters, broken wires, poor voltage supply and faulty limit switch or capacitor.
The blower motor relies on a capacitor to start and run smoothly. Set your multimeter to measure capacitance and connect the probes to the capacitor terminals. A reading that matches the capacitor's rated value indicates it is functioning correctly.
Overheating is one of the most frequent occurrences that can render the blower motor inoperative. If the motor has overheated, it may shut itself down to prevent damage. You should keep your HVAC clean and clear of any blockages or debris to avoid overheating and maintain efficiency.
The fan stops blowing air: Anyone who has driven a car will realize that there is a problem when the fan isn't running when the air conditioning is on. If the cooling fans are not running at all, then this may be a sign that the fan control module is damaged.
The replacement of the blower motor is common and straightforward, so most shops will perform the repair — many on the same day.
The blower motor resistor controls the speed of the fan and is critical in regulating the temperature and airflow inside the vehicle. If the resistor fails, the air conditioning and heating system may not work properly, which can affect passenger comfort.
The average cost for a Blower Motor Resistor Replacement is between $119 and $154. Labor costs are estimated between $43 and $54 while parts are priced between $76 and $99. This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.
The AC system is responsible for circulating air through the system and into your home. Therefore, if you notice that there is low or no airflow from your vents, it's an indication there may be a problem with your blower motor that needs repair or replacement by a professional.
The engine will stop running, and your vehicle won't move or start. Main relay problems could also lead to your engine running for a while or a very short time. Your vehicle might start normally sometimes but not start at all at other times.