The blower motor resistor is responsible for controlling the blower motor speed. In the past, this was done by varying the voltage supplied to the blower motor. In newer applications, the blower motor resistor is actually a solid state module that sends a varied signal to the blower motor.
What is used to control a blower motor?
Blower resistors are resistors which are used to control the fan speed of automotive blowers. The fan speed can be changed either by switching the blower resistor resistance mechanically using a rotating lever, or electronically by the air conditioning system.
What does a blower motor regulator do?
The Blower Motor Regulator controls the speed of the blower motor in your vehicle's heating system. The regulator consists of a set of three resistors or terminals that generate a voltage to vary the speed of the motor. Each speed setting of the fan causes the current to flow through a combination of the resistors.
What relay controls the blower motor?
The blower motor relay controls the current used to power the blower motor, and is subject to the constant on and off switching.
Where is the blower motor resistor?
The heater blower motor resistor is often found beneath the dashboard. It is located in the heater and air conditioning compartment. It's connected to the air conditioning system, where it can adjust the speed of the blower motor fan. It can also be found behind the glove box of some vehicles.
How do I control my blower speed?
You can increase or decrease the blower speed by slightly adjusting the pulley on the blower drive motor. To increase blower speed, slightly loosen the setscrew that holds the pulley to the driveshaft. Move or turn the pulley clockwise on the shaft one turn, then tighten setscrew.
How does fan speed control work?
They control the voltage across the fan is controlled by a capacitor, the voltage across the fan determines the fan speed. Capacitive regulators are energy efficient with linear speed control, quiet operation without humming noises and highly reliable than electronic type regulator.
How do you know if blower motor resistor is bad?
Signs of a Bad Blower Motor Resistor Loss of HVAC fan control (total or certain speeds) The fan only works on its highest speed setting. No air coming from vents. Intermittent or inconsistent fan speed.
What happens when blower motor resistor goes out?
If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.
Is there a fuse that controls the blower motor?
Many vehicles have two fuses for the blower motor, one in the interior fuse block and the other under the hood. The blower motor is usually under the dashboard on the passenger side.
Where is the blower motor relay fuse located?
Under the instrument panel, look under the glove box. On the right side of the fender wall you will find another fuse box. The blower motor fuse is easy to replace.
Does a blower motor resistor have a fuse?
A fuse is often located on the resistor board. The fuse only protects the low and medium blower speeds. High speed will still work if the resistor fuse is blown.
Will a blower motor work without the resistor?
Without any power, the motor won't run. As a result, the blower fan stays still and silent, and no air blows out of the vents. There are instances where a bad resistor will prevent the current from reaching the blower motor altogether.
How do I change the blower motor resistor?
Locate the blower motor resistor. It can be found below the blower motor. In some vehicle's you need to remove the glove compartment to access the blower motor resistor. Now that you've located the blower motor resistor, you'll now need to disconnect the resistor from the housing and then remove the harness.
How do I test a blower motor resistor?
Place one lead of the Ohmmeter on terminal 1 of the resistor. Place the other lead on terminal 2 and check against specifications. If this circuit is open, showing infinity on the Ohmmeter, the blower resistor must be replaced. Move the lead from terminal 2 to terminal 3 and check this reading against specifications.
Which are the three most common types of blower controls?
The three types of fans most commonly found in HVAC systems are the following: Axial fan. Forward-curved centrifugal fan. Backward-inclined fan.
What does a blower control switch do?
What Is a Blower Control Switch? The blower control switch controls the speed of the fan in the heating and air conditioning system of a vehicle. It works with the blower motor to deliver the right temperature and airflow needed to cool down or heat up a car's cabin.
Where is the blower motor capacitor?
It's common for HVAC blower unit fan motors to use a start/run capacitor. Those will be located in the blower cabinet, often right on the blower motor itself.
Are ECM motors variable speed?
The word “variable speed” refers to the blower motor that is inside your air handler or furnace. It is an ECM (electronically commutated motor).
How do you control fan speed with a regulator?
In order to regulate the fan speed, a regulator is provided which varies the voltage across the winding and thus controls the speed. Lower the voltage lower the speed of the fan. So a regulator controls the voltage levels for the fan.
Does capacitor affect fan speed?
A higher value of capacitor does help in increasing the speed of the fan as a capacitor is basically used in a fan to create a phase difference between the currents taken by the main winding and the starting winding of single phase IM used in the fan.
What does a capacitor do on a fan?
The capacitor is used not only to start the fan but also to make it spin. In simple words, the capacitor creates a magnetic flux (torque) which makes the fan rotate. Generally, two capacitors in parallel series are used in the ceiling fan.
Does a blower motor have a relay?
In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.
What causes heater blower not working?
If little air is coming through the vents (hot or cold), then it could be because the blower motor for the fan or a switch or resistor that controls fan speed isn't working. Another cause might be that the electronically controlled “blend doors” that direct air flow are stuck or broken.
Where is the blower motor capacitor?
It's common for HVAC blower unit fan motors to use a start/run capacitor. Those will be located in the blower cabinet, often right on the blower motor itself.
What is the difference between blower motor and blower motor resistor?
The blower motor resistor is responsible for controlling the blower motor speed. In the past, this was done by varying the voltage supplied to the blower motor. In newer applications, the blower motor resistor is actually a solid state module that sends a varied signal to the blower motor.
What is a blower motor and how does it work?
Even a small motor is capable of moving a large volume of conditioned air. There are basically two types of blower motor: the single-speed blower motor and the variable-speed blower motor. A single-speed motor blows air at only one speed and full capacity when it’s operating. It turns on and off according to the thermostat’s instructions.
How does a blower fan resistor work?
The blower resistor is connected in series with the blower fan. This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack.
Where is the blower motor located on a car?
Blower motor, resistor: how it works, symptoms, problems, testing. The motor that runs the fan in the heating and air conditioning system in a car is called a blower motor. It's located inside the dash, often on the opposite side of the steering wheel or inside the engine compartment on the firewall.
Why is my blower motor stuck at a certain speed?
Because the blower motor resistor adjusts the fan speed, the inability to change it can point to problems. If the resistor fails or shorts, the blower motor might remain stuck at a particular speed. While you could still use the air conditioning or heater at his speed, you will want to repair it for complete functionality again.
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