How do you test a blower motor with a multimeter?

Using a multimeter set on the Ohm scale, use the positive lead and test the black wire. To check the purple wire for current, use your ignition key and turn it to the run setting, turn the heater power to full power and set the multimeter to DC power. If your meter reads "no current" the motor is no good.

.

Similarly one may ask, how do you test a blower motor?

If the blower motor isn't running you should:

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

Similarly, how many volts should a blower motor receive? Typically it's done by measuring the voltage at the blower motor connector when it's turned on. If there is a voltage at the motor (at least 4-6 Volt at low speed and 12 Volt at high speed), but the motor doesn't run, the motor is bad or jammed.

Subsequently, one may also ask, how do you test a blower motor resistor with a multimeter?

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.

What are the symptoms of a bad blower motor?

Symptoms of a Bad or Failing Heater Blower Motor

• Weak airflow from the vents. One of the first symptoms of a potential problem with the vehicle's heater blower motor is low airflow from the vents.
• Fan only blows at certain speeds. Another symptom of a bad or failing heater blower motor is a motor that only functions at certain speeds.
• No air from the vents.

Related Question Answers

Where is the blower motor fuse?

Locate the fuse panel just beneath the dashboard on the driver side of the car. Remove the screw securing the fuse panel cover and remove the cover.

How do I know if I have blower motor or resistor?

Symptoms of a Bad or Failing Heater Blower Motor Resistor

1. Blower motor stuck on one speed. A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting.
2. Blower motor does not work on certain settings.
3. No air from the vehicle's vents.

What can cause a blower motor to stop working?

In a situation where the motor doesn't work on any speed, the most likely causes are: a blown power supply fuse, a bad motor ground connection, bad motor speed control module or a failed motor. On all systems, a failed blower motor is least likely. Start by checking the blower fuse and HVAC controller fuse.

How do you know if a resistor is bad?

Set a digital multimeter for "ohms." Set an ohms range that is equal to or higher than the value of the resistor to be tested. Touch the red lead from the meter to one side, and the black lead to the other. Resistors do not hold a polarity, so it doesn't matter which side gets the red or black lead.

What happens when a blower motor resistor goes bad?

If you have faulty blower motor resistor you may experience low airflow coming from the vents even when the fan is all the way on high. In some cases bad blower motor resistor may not even turn the blower motor fan as a result your fan will not work at all and there will be no air coming from the vents.

How do you troubleshoot a blower motor resistor?

How to Troubleshoot a Blower Motor Resistor

1. Locate the fuse for the blower motor in the owners/service manual.
2. Unplug the blower motor and test for power using the 12-volt test light in the same manner as explained in Step 1.
3. Test for ground at the blower motor if there is power indicated at all ranges, but the motor does not function.

Can you bypass blower motor resistor?

This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. 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.

How much is a blower motor resistor?

Know what price you should pay to get your vehicle fixed. The average cost for a blower motor resistor replacement is between $119 and $161. Labor costs are estimated between $47 and $60 while parts are priced between $72 and $101.

What is a blower motor resistor?

The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. It is responsible for controlling the blower motor's fan speed. A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system.

How do you check a relay?

Listen for a click when the relay is energized. Check the energized condition of the relay contacts. Use a digital multimeter (DMM) to test the resistance between each pole of the relay and the corresponding NC and NO contacts for that pole. All NC contacts should read infinite resistance to the corresponding pole.

How do you test an amp blower motor?

HOW TO MEASURE BLOWER MOTOR AMP DRAW

1. Test Instruments.
2. First, Safety.
3. The Test Procedure.
4. Open up the blower compartment of the furnace or air handler.
5. Check the rotation of the fan.
6. Locate the power wire leading to the blower motor.
7. Connect the amp clamp from your electrical meter around the power wire.
8. Read the amp draw of the blower motor.

How long does it take to replace a blower motor resistor?

about 45 minutes

How do you test an electric motor?

With an ohmmeter set to the Resistance or Ohms test setting, place test probes into the appropriate jacks, usually the "Common" and "Ohms" jacks. (Check the meter's operation manual if necessary) Choose the highest scale (R X 1000 or similar) and zero the meter by touching both probes against each other.

How do you test a fan motor?

How to Test Your AC Fan Motor

1. Check the power. If you suspect the fan motor is bad, the first thing you should check is the power to the motor and the power to the air conditioning unit.
2. Check the windings. Next, check the windings of the fan motor for an open or a short.
3. Inspect the capacitor.

How many amps does a blower motor use?

20 amps for a blower on high sounds correct. 20 amps is a lot of current, doesn't take much resistance to drop voltage a noticeable amount. For example, 20 Amps through a tenth of an ohm resistance would give a voltage DROP of 2 volts (V = I x R, so 20 Amps times . 1 Ohm = 2 Volts).