How To Check Blower Motor Resistor With Multimeter

August 31, 2024 Post a Comment

How to check blower motor resistor with multimeter

If you want to do a quick test of the blower resistor, you can check the resistance of each of the resistors with a multimeter as follows: set the tool to read ohms (a measurement of resistance) and connect one of its probes to the common output terminal of the resistor.

How do I know if my 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.

How do you check blower motor ohms?

So red and white the resistance reading is 8.3 ohms of resistance. From white to blue blue the

Can a blower motor resistor be bypassed?

In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car's battery, which allows maximum current through the motor.

Is there a fuse for blower resistor?

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.

What causes blower motor resistor failure?

In most cases, the blower fan resistor is failing either due to overheating or corrosion. If the blower fan fails, your car will not blow any forced air. However, sometimes the problem can be with the blower motor itself. This is especially apparent when you have replaced the blower fan multiple times.

Can a bad resistor ruin a blower motor?

A defective resistor can seize all the power going to the blower motor resulting in no air pressure

Can you fix a bad blower motor resistor?

The average cost to replace the blower motor resistor at a repair shop is between $44 and $55 in parts and $70 in labor costs, for a total cost of around $114 to $125. On the other hand, you can easily fix the blower motor resistor at home in about an hour (even if you're a beginner) and for around $70.

Should I replace both blower motor and resistor?

We do suggest that you replace the resistor at the same time. It may not be critical, but this will keep the system more uniform. The issue may even be related to the resistor. If you know that it is not related to the issue, then you do not have to replace it.

How many ohms should a blower motor resistor have?

How Many Ohms Should A Blower Motor Have? A good blower motor is expected to read over 0.5 Ohms.

Should a blower motor have continuity?

The first step is to insure that there is continuity between the three terminals. Check black to white, black to red, and red to white. All should have continuity. Then check resistance.

What is a good ohms reading for a motor?

A good motor should read less than 0.5 ohms. Any value greater 0.5 ohms indicate trouble with the motor.

Does the blower motor resistor have anything to do with the AC?

The blower motor resistor in your car is the part that is responsible for pushing air through the vents when using the air conditioner or heater. The blower motor resistor is constantly put under stress which can cause it to eventually fail.

How do you test a blower motor relay?

Connect a test light or multimeter to the ground (black lead). Turn the ignition key to the on position (engine off), and remove the relay. Using the probe, test all terminal sockets in the relay connector. Two of the four should have power.

What does the blower motor resistor connect to?

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.

How do I know if my blower motor fuse is blown?

How to check the blower motor fuse? With the fuse box located and the blower, motor fuse identified, go ahead and remove it and check the filament. If it's broken, the fuse is blown. Replacing the fuse may solve the problem or you may find it blows again either immediately or shortly thereafter.

How long should a blower motor resistor last?

The blower motor resistor is designed to last for the car's lifespan. In most cases, these resistors will wear out long before the car does. Usually, the wear that the blower motor resistor has is due to the constant use that it gets and the heat that it is exposed on a regular basis.

How do I reset my blower motor?

Follow these simple steps: First, turn off the power supply to the furnace by turning off the breaker in the circuit box. Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor.

How do you diagnose a blower motor problem?

If the blower motor isn't running you should:

Use voltmeter or ohmmeter to check for a blown fuse. If you find one, replace it.
Start car and see if blower motor works.
If the circuits are in good repair but the blower motor keeps blowing fuses, replace the blower motor [source: You Fix Cars].

How do you diagnose a blower motor failure?

What are the symptoms of a bad blower motor?

Low/no airflow from vents. The classic sign of a bad blower motor is restricted airflow coming from your air vents.
Strange sounds coming from blower. ...
Circuit breaker keeps tripping. ...
Hot/burning smell coming from air vents.