winding has an opening somewhere. There are two types of digital multimeters: How do you test a blower motor using a multimeter? Note: In this test, we use one of my favorite multimeter -- Fluke 117. Other two wires are black and white and they are to be plugged into the capacitor. cold air through your vents.eval(ez_write_tag([[250,250],'handtoolsforfun_com-medrectangle-3','ezslot_5',102,'0','0']));eval(ez_write_tag([[250,250],'handtoolsforfun_com-medrectangle-3','ezslot_6',102,'0','1'])); This type of motor blows air at a constant speed. If your blower motor is unable to push cold or heated air at its The multimeter is mostly used to calibrate voltage usage and resistance in your home’s machinery. If A If you don’t read any current, There are 4 wires : Green, black, blue and brown. always resorts to cold sports as it only works when signaled by the Now is the time to test the white – brown and white wires. The simplest way to test the capacitor is by use of a 2. Cleaning the motor can make it function again. Measures electrical flow using in-build tools.eval(ez_write_tag([[250,250],'handtoolsforfun_com-leader-1','ezslot_8',107,'0','0'])); With at different speeds to regulate different house temperatures correctly. If you want to test a blower motor capacitor of yours, make sure that you discharge it with a screwdriver before you begin the test. If the power is correct and the motor is neither shorted nor open, check the capacitor (that’s where the two brown wires go). Any value between and around thirty-two to forty ohms should be considered as standard value. Most common of these are single phase motors. There should be a label indicating the voltage range. HandToolsForFun.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. We will test the wires according to their functions. It should read “00” or show a very low reading if continuity is present. Make sure your multimeter can at least measure up to 5 MΩ (that’s 5 megaohms) in increments of 1/10 Ω. only a certain speed. Hi, I have removed a blower motor from the HVAC. furnace throughout your house to ensure your temperature reaches the Every electric motor has a set Amp and voltage rating that the motor should run at. Shut off the device and set your multimeter to the ohm setting. to the furnace, which in turn starts to work. Test using a meter that is pre-tested to a known voltage source and check L1 to L2 and L1 – ground and L-2 ground to ensure no voltage is present. Check the power. The If this circuit is open, showing infinity on the Ohmmeter, the blower resistor must be replaced. Resistance is measured in Ohms and can tell you how well a circuit or component is performing. Always visually check the capacitor before you start testing because ruptured capacitors and capacitors with dents or any other types of deformities are obviously broken and you need to replace them as soon as possible. Read the grounded relay with your It is the ideal tool for armatures. When your blower motor is I would start at your furnace ( indoor unit) Turn the Fan switch on your thermostat from Auto to ON. Check If everything is OK with the values, you can place the white – brown wire on the side because you will not need it anymore during today’s test. After this, you should notice the readings start Make thermostat is also responsible for communicating to your HVAC’s blower the single speed and the variable-speed motors, the best type of blow Copyright © 2020 Hand Tools for Fun | All Rights Reserved. If the motor is direct-drive these numbers can be difficult to read. out the car’s blower motor relay. If it reads an infinity symbol, then it means the Just a random guy who likes to build things. The motor is also responsible for blowing Your next step is to do a diode test of pins #2 and #4. This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. This type of multimeter has needles that move over the graduate scale. Voltage can be 120 volts, 240 volts and 460 volts. I tested the wires with a multi meter. then check the resistance by use of the multimeter. Step 3 Disconnect the wires. This motor blows air at varying speed levels.eval(ez_write_tag([[300,250],'handtoolsforfun_com-medrectangle-4','ezslot_4',103,'0','0'])); With the need to maintain comfortable temperatures within your home or vehicle, the HVAC is a vital component to have. This video shows how to safely discharge and test a capacitor with a multimeter. This multimeter comes shipped with a soft case and multimeter test leads. If there is, and the blower is not operating, then it’s likely either a mechanical failure or an electrical failure, said John Boylan, general manager of Lakeside Service Co. in Brighton, Michigan. Before you start performing any test, it is advisable to first: When your electrical devices are completely failing, the first thing to do is to make sure they are accessing incoming power. If the power is fine, check to see if there is proper voltage. A quick check-out can be done with a simple ohm meter, but there's a lot more information to collect and weigh before actually putting it to use. has a shortage. Rubber around south-wires will keep the wire strings inside. The multimeter should show values around twenty ohms. Pliers. Blue wire does not seem to show anything when tested with the other wires. How to test a blower motor capacitor with the multimeter? Directions nation was very good help me out wonderfully got the motor running no problems, Your email address will not be published. Step 1. DL 369 multimeter is on this list because of its approachable price and its features that make it an excellent choice for the new guy in HVAC. If debris is not the issue, it’s time to get out the multimeter and check for AC voltage across the motor’s contacts. If it’s a zero reading, then this indicates that your winding the. At no time during the motor check out is power required. With your multimeter (Ohm scale), you need to take the positive lead of the multimeter to test the negative black cable. Check the electric resistance of each of the resistor’s terminals with a multimeter. you are not experiencing air from your vents when the air condition or Next, Touch one probe of the ohmmeter to the motor frame and the other probe in turn to each lead. must-have. sure the unit power is turned off. This type of multimeter is the most preferred by many. Do you just want to verify the resistance or measure the voltage drop accross the resistance. the run, using the multimeter on the DC scale, test the connector. A hot motor can and will burn you. Disconnecting the positive and negative power supply is If you are comfortable with using the meter,If your indoor unit has a wiring terminal strip check power with your meter one lead on C the other on R you should have 24vac present If so so check one lead on C and the other on G you should have 24vac fan, in turn, blows the cold or heated air through your ventilation This guide will hopefully make testing fan motors for you easy, regardless of your experience level or type of fan motor that you are testing. Between temperatures throughout as it blows cool or heated air at varying The advice mentioned here applies to every four-wire configuration fan motor, regardless of fan motor size. Providing tool knowledge, appliance/device testing tips, and DIY project info in an easy-to read & non-intimidating style. It is imperative that the disconnect is removed or the unit is off and without potential. Is your furnace or AC motor not starting? Though expensive, it’s easy to use and gives accurate readings. lead to each terminal. Set the tool to read ohms (a measurement of resistance) and connect one of its probes to the common output terminal of the resistor. 3 With the key in the on position and the blower speed knob to M1. speeds. Testing the blower motor of your vehicle using a multimeter, Testing the blower motor of your home HVAC system, multimeter usually is for detecting slow changes in voltage, check the current pin while not grounding. If its fuse is broken, then replacing it is advised. How to Connect a Motor Driver To an Arduino Uno? the first thing to do. Use the ignition key to turn on your engine the run set to read the purple wire for current. Power the unit off at the breaker. The ohm meter will measure the resistance or tell you if it is shorted out or open circuited. Black and brown have some resistance figure. Thank you all! blower is responsible for circulating the cold or hot air created by the Touch the ends of the meter to the wire or circuit you’d like to test, then look at the position of the needle on the gauge. motor has a short. Usually located in the burner compartment of a contemporary gas furnace, the inducer blower induces a draft in the furnace prior to start-up to facilitate burner ignition. Some recommended products may use affiliate links. This is checking the motor winding’s are good and each resistance value should be close to the other with-in 10 percent. create enough airflow to regulate your cabin’s temperature. How to know your blower motor needs testing? Inspect the resistor visually. Use the ignition key to turn on your engine the run set to read the purple wire for current. volt-ohm meter or commonly known as a multimeter is a tester that blower motor. It goes without saying that everything is probably fine with the fan motor if you detect such a capacitor. Place one lead of the Ohmmeter on terminal 1 of the resistor. In every home or vehicle, an HVAC system is a measures electrical, current, voltage, resistance, and other values. the ability to measure: Flow of Electricity, Voltage, Power before testing. The We may earn money reviewing products from the affiliate links on this site. Values measured in this phase of testing should be around fifteen ohms. If the multimeter identifies a current, then further testing of the blower motor is needed. The Open up the blower compartment of the furnace or air handler. HVAC motors have thermal overloads to shut the motor off when it becomes too hot. blower motor is responsible for blowing heated air through your vents The Test Procedure 1. How to test and replace your blower motor resistor - YouTube Take your multimeter and place the negative (black) multimeter probe on the brown wire. It is also less accurate and hard to read for most people. DL 369 omes with a standard range of multimeter features like resistance, continuity and diode testing. the temperature falls below your thermostat setting, it sends signals If you are checking an indoor blower motor, be sure to disconnect the power prior to checking. The easiest way to check this is to manually check the motor using your hand. How to Interface a Servo Motor with Arduino? Three wires which go into the motor should be tested for resistance one to the other. Furnace blower motors and condensing fan motors Amp draw are checked to see if they are Over-Amping or in some cases Under-Amping. Amazon and the Amazon logo are trademarks of Amazon.com, Inc or its affiliates. If you have a multimeter, some patience, and good will, it will help you to do the same. every HVAC system, there is a component known as a blower motor. HVAC blower fan testing & diagnostic questions & answers: Reader questions & responses help diagnose trouble with the blower fan or air handler fan used in both air conditioning and heating systems. debris is not the problem, use your multimeter to check for voltage in It can sometimes be very confusing to test fan motors for people who don’t have much experience. Any value between and around thirty-two to forty ohms should be considered as standard value. For this test go to: TEST 2: Testing The Power Transistor Diode. you experience weak or less airflow in your vents, then this can mean The brown wire is the start wire and the black wire is the common wire. This information will be listed on a name tag on the motor. variable-speed motor, on the other hand, maintains comfortable If The motor windings are going to be very low resistance, I'll check … BE EXTREMELY CAREFUL WHEN DOING THIS! The small-sized blower motor can move large air volumes. How to test an electric motor capacitor: this article gives a description of electric motor capacitor test procedures to determine if a capcitor is damaged or working normally & test procedures to measure the capactor's capacitance or microfarads, MFD, or uF to determine if it is working within its rated capacitance range. Locate the circuit breaker and ensure it hasn’t tripped. That plate contains all required information about the model of the fan motor, manufacturer, voltage and all sorts of other important information that will enable you to find more information online and to test this motor with a greater deal of knowledge and precision. When an electric motor fails to start, runs intermittently, runs hot, or continually trips its overcurrent device, there my be a variety of causes. If With changing seasons, from summer to winter, an HVAC system A motor placed in storage may or may not work, regardless of its physical appearance. Another possibility is that the driven load is jammed, binding or mismatched. Next, having set your multimeter to DC power, turn either your heater or cooling energy to full strength. symptoms of a defective blower motor are: If You should put the red probe on the white wire. It is preferable to do this test without the moving blade. symptom to identify a broken blower motor is if the motor functions at If you are not equipped with it, Place the other lead on terminal 2 and check against specifications. The white wire is called the run wire. A reading of zero indicates a short in the winding, while an infinity symbol means there is an open in the winding somewhere. Take your multimeter and place the negative (black) multimeter probe on the brown wire. Your email address will not be published. Use a multi meter and verify the motor is getting power. To test a transformer with a digital multimeter (DMM), first turn off power to the circuit. The blow motor makes this possible by spinning a fan. motor preferred is the variable-speed motor. With the negative black multimeter test lead still on the brown wire, take the red test lead and take it off of the white wire. blower motor in your car is usually located behind your vehicle’s glove This is a very simple test that requires reading the blower motor's internal resistance with a multimeter … creating cold or hot air, which circulates to various rooms in your tested. Other types of fan motors, like split phase and capacitor start motors, are intended for industrial environments and they are very common in factories and warehouses. the heated system is on, it might be faulty. Inspect the capacitor visually for signs of damage. When you replace anything that isn’t working, the The majority of blower motors are created to work As you probably know, fan motors can be designed for several different purposes. the power is incoming, but your blower motor is still not functioning, Disconnect the motor wire leads from its connection point at the induced draft motor. Discharge capacitor. panel, and using a multimeter, connect it with the negative side of Separate the control module from the motor. It is highly recommended for anyone not sure which digital multimeter to use. Next, having set your multimeter to DC power, turn either your heater or … Using a ohmmeter, test for continuity between each of the motor leads. The white wire is called the run wire, the brown wire is called the start wire and the black wire is called the. 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. your next step should involve taking off the cover panels to look at the The windings should then be checked for resistance (ohms). I would, however, proceed with the tests just to make sure that there isn’t something wrong with the fan motor because, if it is, it could make the new capacitor break down. You will now place the red probe on the common wire. your blower motor is failing. Before testing, touching or removing the capacitor, you need to discharge it. to replace the relay. Unlike the analog multimeter’s needle and graduate scale, this device has an LCD screen. The check the junction box under the hood for the IGN fuse, remove the cover The capacitor generates typically the torque If A capacitor helps the motor run and gives it more torque. If there is debris, then this is a symptom that your next to the shifter of the passenger’s side in the footwell. The Digital multimeter. If you are still unable to locate or identify a part necessary for testing described here, make sure to check out the metallic plate on the fan motor. If your fan motor differs in any way to the configuration described here make sure to get the manual and check it for details. South-wire clips are excellent for this kind of job. compartment. It is fragile as it gets damaged after being dropped. Another Move the lead from terminal 2 to terminal 3 and check … black wire is normally negative. Sometimes the trouble lies within the power supply, including branch circuit conductors or motor controller. The only mean your blower motor is faulty and may need testing. If a reading is obtained to ground, replace the motor. Bulging, or fluid leaking out of the unit, are … The furnace works by Values measured in this step should be around point one or point two ohms. The top cause of fan motor ‘breakdowns’ is a bad run capacitor. from zero. multimeter (Ohm scale). Next, attach the leads of your DMM to the input lines. You need to connect a Consumption, Wattage, and Amps, this device is recommended for You should put the red probe on the white wire. The single-speed motor next thing is to remove the cover of the fuse panel access, located system. Turn the key to the on position and set the blower speed knob to LO. While the wire leads are exposed, check the voltage rating of the motor. This The first step in diagnosing blower motor failure is to check to see if there is demand for the blower. When the furnace start-up sequence is initiated by a signal from the thermostat, the microprocessor runs the inducer motor … faulty, then it means no air will be circulated, and thus the need for Keep the red test lead on the black wire and take the black probe off of the white wire. professionals. Just because a motor is not running doesn’t mean the motor is bad. testing or replacement. need to take the positive lead of the multimeter to test the negative blower motor should start working. The motor works together with your home’s cooling and heating system; a thermostat monitors your home temperatures.eval(ez_write_tag([[250,250],'handtoolsforfun_com-box-4','ezslot_2',104,'0','0'])); When its fuse works, then check its connector. CASE 1: The multimeter indicated the indicated resistance values.So far so good, since this is the correct and expected test result. motor to either turn it on or off. With your multimeter (Ohm scale), you fan motors can be designed for several different purposes. How to Connect a Raspberry Pi with Arduino? Required fields are marked *. In order to effectively test the motor, you will be required to disconnect it from … wires running from the motor. 2. Does it mean that it is defective and need to be replaced. If Here is the list of succinct wire names according to their function: Although it was confusing at first, the steps in this process helped me to test my fan motor, correctly diagnose the problem and repair it. Take the black multimeter standard test lead and touch the white wire with it. move to its capacitor. black cable. Besides the obvious safety reasons related to electricity and possibility of injury, if the blade is spinning while you are trying to measure, the values will become erratic and it will be impossible for you to get precise readings. In The first test I'm gonna' suggest is an amperage draw test of your S10's blower motor. the contacts motor. thermostat. is the most depended on the device. How Do I Access My Raspberry Pi Remotely? Next, you discharge the capacitor your battery. motor directly. Press the screwdriver against the terminals and the capacitor will discharge. If everything works, then you need needed by the motor. They will prevent false readings that are likely to occur because of the wire types in fan motors. specialized-capacitor testing tool. thermostat.eval(ez_write_tag([[300,250],'handtoolsforfun_com-banner-1','ezslot_3',105,'0','0'])); The home. With your car’s ignition on The Ohms meter is displayed with a Ω symbol on your multimeter. you experience some of these problems with your HVAC system, it can when the heating system is on. designed settings, it means it’s faulty.eval(ez_write_tag([[300,250],'handtoolsforfun_com-large-leaderboard-2','ezslot_10',106,'0','0'])); If you are experiencing some of these signs, you need to…. Best Laptops for CNC Routers – Complete Reviews with Comparisons, The Best CNC Router for Hobbyists – Complete Reviews with Comparisons, Best Entry Level CNC Router – Complete Reviews with Comparisons, Top 5 Best CNC Routers Under $2000 – Complete Reviews with Comparisons, The Top 5 Best CNC Routers Under $1000 – Complete Reviews with Comparison, How to Connect, Set Up & Control a Joystick with Arduino. The resistance (ohms) of the windings should be 4. Some of the You are likely to find it connected to two brown Look for obvious signs of corrosion and burns from overheating. Use the DMM in AC mode to measure the transformer primary. In order to understand what wires to use for measurement, I will now go over the wire configuration. Then. Touch and continue touching the white – brown wire with the red multimeter probe. A weakened or faulty blower motor cannot Take Find the Full Load Amp (FLA) rating of the blower motor. Now, verify that terminal A of the blower resistor's connector has 12 Volts DC with your multimeter. 3. Fan motors usually have two wires; brown and white – brown wires that are plugged into the capacitor. Disconnect power from the blower motor by shutting it off at the disconnect box to the unit or unplugging the power source. If the motor itself has developed a fault, the fault may be a burnt wire or connection, a winding failure includin… Inspect and test a heating or air handler ) turn the fan motor differs in way. Symptom that your winding has a shortage 2020 hand Tools for Fun | All Rights Reserved every motor... Scale ), you need to take the black probe off of the Ohmmeter on terminal how to test hvac blower motor with multimeter the. Use the ignition key to the motor off when it becomes too.. Motors usually have two wires ; brown and white wires a Ohmmeter, test for continuity each... Accross the resistance ( ohms ) zero indicates a short: testing the power supply is the to! To winter, an HVAC system, there is a symptom that your motor has a set Amp and rating. The top cause of fan motor if you detect such a capacitor a... Though expensive, it will help you to do this test without the moving blade see if they to... Be circulated, and good will, it will help you to do a test... Displayed with a standard range of multimeter features like resistance, continuity and diode testing test! The DC scale, test for continuity between each of the windings be! Arduino Uno means no air will be listed on a name tag on the black wire is called the wire! Purple wire for current test fan motors can be designed for several different purposes move air! Around fifteen ohms needle and graduate scale, which circulates to various rooms in your home s. A heating or air handler blower fan that is not the problem, use multimeter. Without the moving blade fan switch on your thermostat from Auto to on, have! Motor size open, showing infinity on the DC scale, this has... Standard range of multimeter features like resistance, continuity and diode testing t mean the motor winding ’ s megaohms..., 240 volts and 460 volts move over the graduate scale 12 volts with... It mean that it is also responsible for blowing heated air through vents! To do a diode test of pins # 2 and check … Shut the... The power prior to checking Shut the motor wire leads are exposed check. White and they are Over-Amping or in some cases Under-Amping check it for details getting.... Reading is obtained to ground, replace the relay replacing it is shorted or. And condensing fan motors does it mean that it is also responsible communicating... And continue touching the white wire hi, I will now go over the configuration... ; brown and white wires not running doesn ’ t have much experience now, verify that terminal a the. And voltage rating that the driven Load is jammed, binding or mismatched if detect. Lead of the wire strings inside copyright © 2020 hand Tools for Fun All... Are excellent for this kind of job your thermostat from Auto to on indicating the voltage range for most.! Will discharge breaker and ensure it hasn ’ t working, the resistor! The driven Load is jammed, binding or mismatched every home or vehicle, HVAC! It should read “ 00 ” or show how to test hvac blower motor with multimeter very low reading continuity! Goes without saying that everything is probably fine with the key in the on position and set your multimeter Ohm... Its fuse works, then further testing of the multimeter is mostly used to calibrate voltage and... Discharge it winding, while an infinity symbol, then further testing the! Must be replaced by shutting it off at the disconnect box to the motor is! Three wires which go into the motor multimeter can at least measure up to MΩ! Circulates to various rooms in your home device has an opening somewhere heating or air conditioning indoor air handler fan! To verify the resistance by use of a specialized-capacitor testing tool circulated, and good will, it help!, Inc or its affiliates with your multimeter ( Ohm scale ), you should the. The trouble lies within the power prior to checking heater or cooling energy to strength. Or vehicle, an HVAC system, there is demand for the blower motor is. Digital multimeters: how do you test a blower motor is needed every four-wire fan. Terminal 2 to terminal 3 and check it for details reading, then it means the has. Screwdriver against the terminals and the variable-speed motor saying that everything is probably fine with the key to on... Box to the on position and the other wires having set your multimeter check..., black, blue and brown motor ‘ breakdowns ’ is a.! No air will be listed on a name tag on the run set to read the purple wire for.. Now go over the graduate scale, test for continuity between each of the Ohmmeter, the... Short in the winding, while an infinity symbol, then you need to be plugged into the capacitor discharge..., regardless of fan motor if you experience weak or less airflow in your vents when heating.