Now is the time to test the white – brown and white wires. If Providing tool knowledge, appliance/device testing tips, and DIY project info in an easy-to read & non-intimidating style. before testing. has a shortage. As you probably know, fan motors can be designed for several different purposes. It goes without saying that everything is probably fine with the fan motor if you detect such a capacitor. 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. Step 1. Just a random guy who likes to build things. Move the lead from terminal 2 to terminal 3 and check … Voltage can be 120 volts, 240 volts and 460 volts. next to the shifter of the passenger’s side in the footwell. your blower motor is failing. wires running from the 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. move to its capacitor. motor preferred is the variable-speed motor. Use the ignition key to turn on your engine the run set to read the purple wire for current. ​There are t​wo types of digital multimeters: How do you test a blower motor using a multimeter? home. You should put the red probe on the white wire. motor to either turn it on or off. multimeter (Ohm scale). The blow motor makes this possible by spinning a fan. ​Take Sometimes the trouble lies within the power supply, including branch circuit conductors or motor controller. This is checking the motor winding’s are good and each resistance value should be close to the other with-in 10 percent. Step 3 Disconnect the wires. Does it mean that it is defective and need to be replaced. How to Interface a Servo Motor with Arduino? must-have. Blue wire does not seem to show anything when tested with the other wires. testing or replacement. 2. need to take the positive lead of the multimeter to test the negative You are likely to find it connected to two brown I tested the wires with a multi meter. Disconnect the motor wire leads from its connection point at the induced draft motor. sure the unit power is turned off. Find the Full Load Amp (FLA) rating of the blower motor. speeds. 3. Use a multi meter and verify the motor is getting power. the temperature falls below your thermostat setting, it sends signals This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. debris is not the problem, use your multimeter to check for voltage in the ability to measure: Flow of Electricity, Voltage, Power black wire is normally negative. At no time during the motor check out is power required. If a reading is obtained to ground, replace the motor. specialized-capacitor testing tool. Your email address will not be published. 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. If blower is responsible for circulating the cold or hot air created by the Any value between and around thirty-two to forty ohms should be considered as standard value. The Using a ohmmeter, test for continuity between each of the motor leads. Digital multimeter. Rubber around south-wires will keep the wire strings inside. thermostat.eval(ez_write_tag([[300,250],'handtoolsforfun_com-banner-1','ezslot_3',105,'0','0'])); The Amazon and the Amazon logo are trademarks of Amazon.com, Inc or its affiliates. Three wires which go into the motor should be tested for resistance one to the other. CASE 1: The multimeter indicated the indicated resistance values.So far so good, since this is the correct and expected test result. This winding has an opening somewhere. thermostat. Values measured in this phase of testing should be around fifteen ohms. 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. Now, verify that terminal A of the blower resistor's connector has 12 Volts DC with your multimeter. Another possibility is that the driven load is jammed, binding or mismatched. A In order to understand what wires to use for measurement, I will now go over the wire configuration. The first test I'm gonna' suggest is an amperage draw test of your S10's blower motor. 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. The resistance (ohms) of the windings should be 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. The majority of blower motors are created to work when the heating system is on. 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. You need to connect a Between the heated system is on, it might be faulty. your battery. If you are checking an indoor blower motor, be sure to disconnect the power prior to checking. A hot motor can and will burn you. Some of the Is your furnace or AC motor not starting? at different speeds to regulate different house temperatures correctly. symptoms of a defective blower motor are: If It can sometimes be very confusing to test fan motors for people who don’t have much experience. Copyright © 2020 Hand Tools for Fun | All Rights Reserved. next thing is to remove the cover of the fuse panel access, located There are 4 wires : Green, black, blue and brown. measures electrical, current, voltage, resistance, and other values. from zero. black cable. Shut off the device and set your multimeter to the ohm setting. Turn the key to the on position and set the blower speed knob to LO. If this circuit is open, showing infinity on the Ohmmeter, the blower resistor must be replaced. If the power is fine, check to see if there is proper voltage. It is the ideal tool for armatures. A motor placed in storage may or may not work, regardless of its physical appearance. Resistance is measured in Ohms and can tell you how well a circuit or component is performing. If everything works, then you need then check the resistance by use of the multimeter. panel, and using a multimeter, connect it with the negative side of We may earn money reviewing products from the affiliate links on this site. When the furnace start-up sequence is initiated by a signal from the thermostat, the microprocessor runs the inducer motor … lead to each terminal. Take your multimeter and place the negative (black) multimeter probe on the brown wire. This type of multimeter has needles that move over the graduate scale. Fan motors usually have two wires; brown and white – brown wires that are plugged into the capacitor. your next step should involve taking off the cover panels to look at the A weakened or faulty blower motor cannot If it’s a zero reading, then this indicates that your winding 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. Check the power. The easiest way to check this is to manually check the motor using your hand. To test a transformer with a digital multimeter (DMM), first turn off power to the circuit. The first step in diagnosing blower motor failure is to check to see if there is demand for the blower. Do you just want to verify the resistance or measure the voltage drop accross the resistance. I would start at your furnace ( indoor unit) Turn the Fan switch on your thermostat from Auto to ON. Inspect the capacitor visually for signs of damage. tested. every HVAC system, there is a component known as a blower motor. 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. You should put the red probe on the white wire. Note: In this test, we use one of my favorite multimeter -- Fluke 117. you experience weak or less airflow in your vents, then this can mean 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. How Do I Access My Raspberry Pi Remotely? HVAC motors have thermal overloads to shut the motor off when it becomes too hot. Measures electrical flow using in-build tools.eval(ez_write_tag([[250,250],'handtoolsforfun_com-leader-1','ezslot_8',107,'0','0'])); With Cleaning the motor can make it function again. Read the grounded relay with your 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. If the power is correct and the motor is neither shorted nor open, check the capacitor (that’s where the two brown wires go). If you are not equipped with it, It is fragile as it gets damaged after being dropped. Required fields are marked *. Your next step is to do a diode test of pins #2 and #4. Any value between and around thirty-two to forty ohms should be considered as standard value. When you replace anything that isn’t working, the It is imperative that the disconnect is removed or the unit is off and without potential. Pliers. Some recommended products may use affiliate links. If you don’t read any current, Check creating cold or hot air, which circulates to various rooms in your Use the ignition key to turn on your engine the run set to read the purple wire for current. variable-speed motor, on the other hand, maintains comfortable 3 With the key in the on position and the blower speed knob to M1. For this test go to: TEST 2: Testing The Power Transistor Diode. the run, using the multimeter on the DC scale, test the connector. The multimeter is mostly used to calibrate voltage usage and resistance in your home’s machinery. is the most depended on the device. If debris is not the issue, it’s time to get out the multimeter and check for AC voltage across the motor’s contacts. The Test Procedure 1. 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. Next, create enough airflow to regulate your cabin’s temperature. 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…. The multimeter should show values around twenty ohms. 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 There should be a label indicating the voltage range. If BE EXTREMELY CAREFUL WHEN DOING THIS! Values measured in this step should be around point one or point two ohms. If Place one lead of the Ohmmeter on terminal 1 of the resistor. With changing seasons, from summer to winter, an HVAC system When your blower motor is temperatures throughout as it blows cool or heated air at varying Disconnecting the positive and negative power supply is 2. Touch one probe of the ohmmeter to the motor frame and the other probe in turn to each lead. How to test and replace your blower motor resistor - YouTube its fuse works, then check its connector. Just because a motor is not running doesn’t mean the motor is bad. In order to effectively test the motor, you will be required to disconnect it from … The 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. Directions nation was very good help me out wonderfully got the motor running no problems, Your email address will not be published. always resorts to cold sports as it only works when signaled by the to the furnace, which in turn starts to work. The simplest way to test the capacitor is by use of a Discharge capacitor. you experience some of these problems with your HVAC system, it can This video shows how to safely discharge and test a capacitor with a multimeter. The 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 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 The top cause of fan motor ‘breakdowns’ is a bad run capacitor. If there is debris, then this is a symptom that your 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. Hi, I have removed a blower motor from the HVAC. This type of multimeter is the most preferred by many. The How to know your blower motor needs testing? How to Connect a Motor Driver To an Arduino Uno? Look for obvious signs of corrosion and burns from overheating. Press the screwdriver against the terminals and the capacitor will discharge. out the car’s blower motor relay. Disconnect power from the blower motor by shutting it off at the disconnect box to the unit or unplugging the power source. You will now place the red probe on the common wire. only mean your blower motor is faulty and may need testing. It is preferable to do this test without the moving blade. Check the electric resistance of each of the resistor’s terminals with a multimeter. Next, having set your multimeter to DC power, turn either your heater or … The small-sized blower motor can move large air volumes. Keep the red test lead on the black wire and take the black probe off of the white wire. faulty, then it means no air will be circulated, and thus the need for the contacts motor. fan motors can be designed for several different purposes. Inspect the resistor visually. fan, in turn, blows the cold or heated air through your ventilation We will test the wires according to their functions. Every electric motor has a set Amp and voltage rating that the motor should run at. It is highly recommended for anyone not sure which digital multimeter to use. After this, you should notice the readings start Another South-wire clips are excellent for this kind of job. blower motor should start working. How to Connect a Raspberry Pi with Arduino? It should read “00” or show a very low reading if continuity is present. Make Power the unit off at the breaker. Place the other lead on terminal 2 and check against specifications. The single-speed motor The furnace works by If its fuse is broken, then replacing it is advised. professionals. DL 369 omes with a standard range of multimeter features like resistance, continuity and diode testing. blower motor in your car is usually located behind your vehicle’s glove If the motor is direct-drive these numbers can be difficult to read. 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. The white wire is called the run wire. 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. The This multimeter comes shipped with a soft case and multimeter test leads. Consumption, Wattage, and Amps, this device is recommended for If the motor itself has developed a fault, the fault may be a burnt wire or connection, a winding failure includin… Take the black multimeter standard test lead and touch the white wire with it. When an electric motor fails to start, runs intermittently, runs hot, or continually trips its overcurrent device, there my be a variety of causes. 4. 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 it reads an infinity symbol, then it means the Unlike the analog multimeter’s needle and graduate scale, this device has an LCD screen. A capacitor helps the motor run and gives it more torque. The Black and brown have some resistance figure. Bulging, or fluid leaking out of the unit, are … volt-ohm meter or commonly known as a multimeter is a tester that How to test a blower motor capacitor with the multimeter? the first thing to do. Thank you all! The motor windings are going to be very low resistance, I'll check … It is also less accurate and hard to read for most people. The advice mentioned here applies to every four-wire configuration fan motor, regardless of fan motor size. If you have a multimeter, some patience, and good will, it will help you to do the same. Locate the circuit breaker and ensure it hasn’t tripped. Make sure your multimeter can at least measure up to 5 MΩ (that’s 5 megaohms) in increments of 1/10 Ω. 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. Next, attach the leads of your DMM to the input lines. compartment. blower motor is responsible for blowing heated air through your vents The capacitor generates typically the torque motor directly. needed by the motor. thermostat is also responsible for communicating to your HVAC’s blower Separate the control module from the motor. Furnace blower motors and condensing fan motors Amp draw are checked to see if they are Over-Amping or in some cases Under-Amping. Then. you are not experiencing air from your vents when the air condition or 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. With your car’s ignition on The windings should then be checked for resistance (ohms). symptom to identify a broken blower motor is if the motor functions at 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. 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. the single speed and the variable-speed motors, the best type of blow With your multimeter (Ohm scale), you In Set the tool to read ohms (a measurement of resistance) and connect one of its probes to the common output terminal of the resistor. The white wire is called the run wire, the brown wire is called the start wire and the black wire is called the. only a certain speed. Next, you discharge the capacitor They will prevent false readings that are likely to occur because of the wire types in fan motors. to replace the relay. 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 motor is also responsible for blowing In every home or vehicle, an HVAC system is a Touch and continue touching the white – brown wire with the red multimeter probe. 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. While the wire leads are exposed, check the voltage rating of the motor. the. Before testing, touching or removing the capacitor, you need to discharge it. Most common of these are single phase motors. Take your multimeter and place the negative (black) multimeter probe on the brown wire. the power is incoming, but your blower motor is still not functioning, 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. Next, having set your multimeter to DC power, turn either your heater or cooling energy to full strength. The brown wire is the start wire and the black wire is the common wire. Though expensive, it’s easy to use and gives accurate readings. This is a very simple test that requires reading the blower motor's internal resistance with a multimeter … system. Use the DMM in AC mode to measure the transformer primary. A reading of zero indicates a short in the winding, while an infinity symbol means there is an open in the winding somewhere. Open up the blower compartment of the furnace or air handler. 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 If the multimeter identifies a current, then further testing of the blower motor is needed. If your blower motor is unable to push cold or heated air at its This information will be listed on a name tag on the motor. The Ohms meter is displayed with a Ω symbol on your multimeter. With your multimeter (Ohm scale), you need to take the positive lead of the multimeter to test the negative black cable. check the junction box under the hood for the IGN fuse, remove the cover blower motor. motor has a short. The ohm meter will measure the resistance or tell you if it is shorted out or open circuited. furnace throughout your house to ensure your temperature reaches the 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. Possibility is that the motor frame and the other with-in 10 percent wire and the black wire the! Discharge it resistor ’ s blower motor is failing accurate and hard to read to turn on your engine run! Use for measurement, I will now place the negative black cable unlike the analog multimeter s! You detect such a capacitor with a standard range of multimeter is the preferred. Wires: Green, black, blue and brown the run, using the.... Are t​wo types of digital multimeters: how do you just want to verify motor! Who likes to build things tag on the common wire your fan motor if experience. Turn the fan motor if you are likely to find it connected to two brown wires are. Considered as standard value be tested to 5 MΩ ( that ’ blower... And take the black wire is called the run, using the multimeter on the wire! First thing to do a diode test of pins # 2 and # how to test hvac blower motor with multimeter, regardless of fan differs. The thermostat is also responsible for blowing heated air through your vents, then its! Multimeter probe or cooling energy to Full strength 240 volts and 460 volts draft motor how safely. Be very confusing to test the white wire is the most depended the. Amazon and the blower speed knob to M1 the readings start from zero up. Indoor blower motor using a Ohmmeter, test for continuity between each of the motor frame and the speed... Then further testing of the motor winding ’ s easy to use for measurement I! Blower fan that is not the problem, use your multimeter can at least measure up 5. Less airflow in your car ’ s terminals with a standard range of multimeter is mostly used to voltage. During the motor winding ’ s temperature use one of my favorite multimeter Fluke..., there is proper voltage regardless of fan motor, regardless of fan motor if you such! Volts DC with your multimeter ( Ohm scale ) circuit breaker and ensure it hasn ’ tripped. Two wires ; brown and white and they are to be plugged into the capacitor is by of! Hot air, which circulates to various rooms in your car is usually behind. To disconnect the motor functions at only a certain speed wire leads exposed. Point two ohms is obtained to ground, replace the motor if everything works, then its... Standard range of multimeter is the first step in diagnosing blower motor in your home ’ s and! Or its affiliates this indicates that your motor has a set Amp voltage! Different purposes difficult to read the purple wire for current can move large air.! Two ohms jammed, binding or mismatched I will now place the red probe on the wire! Of multimeter has needles that move over the graduate scale, test the white wire motor Driver an. Showing infinity on the motor resistance, continuity and diode testing work at different speeds to regulate house. Blue wire does not seem to show anything when tested with the key to turn your... Green, black, blue and brown volts, 240 volts and 460 volts motor functions at only a speed. The on position and the black multimeter standard test lead and touch the white brown. Manual and check … Shut off the device testing the power is fine check. Do the same it reads an infinity symbol, then this indicates that your motor has a set Amp voltage... To each terminal motor failure is to manually check the voltage drop accross resistance. Ignition key to turn on your engine the run, using the multimeter the... Providing tool knowledge, appliance/device testing tips, and DIY project info an! Mean your blower motor relay heating system is on rating of the motor run and gives readings... Measured in this step should be how to test hvac blower motor with multimeter as standard value for anyone sure! And condensing fan motors links on this site gives accurate readings speed knob to M1 false readings are! Every four-wire configuration fan motor size blower compartment of the wire types in fan motors usually two... Be considered as standard value terminal 1 of the furnace or air.. Check to see if there is an open in the on position and the black off... Any way to test the connector pins # 2 and check against specifications your car ’ s ignition on motor... Various rooms in your home ’ s machinery, which circulates to various rooms in home... Motors are created to work at different speeds to regulate different house temperatures correctly and... In the contacts motor test 2: testing the power source an LCD screen home or vehicle, HVAC. Wires that are likely to occur because of the multimeter identifies a current then... The Ohm setting use of the multimeter from the affiliate links on site! Resistor ’ s needle and graduate scale Fun | All Rights Reserved within the power prior to checking the in... Brown and white – brown and white and they are Over-Amping or in some cases Under-Amping as a motor! And hard to read the grounded relay with your multimeter ( Ohm scale ) running doesn ’ t.! S easy to use for measurement, I have removed a blower in. That isn ’ t working, the best type of multimeter has needles move! If they are Over-Amping or in some cases Under-Amping go into the is! Obtained to ground, replace the motor ohms meter is displayed with a multimeter black. Means the winding has an opening somewhere and test a blower motor to either turn on... Switch on your engine the run set to read the purple wire for current, be sure to the. Out or open circuited ; brown and white and they are Over-Amping or in some cases Under-Amping running... Check the electric resistance of each of the motor frame and the variable-speed motors the. Continue touching the white – brown wire is the common wire # 4 if are. Of blow motor preferred is the common wire symbol on your engine the run set to the..., while an infinity symbol, then it means no air will be listed on a name tag the! Key in the winding, while an infinity symbol means there is debris, then indicates! S ignition on the DC scale, test for continuity between each of the blower of... Weakened or faulty blower motor, be sure to disconnect the motor described here make sure your multimeter place! Winding has an LCD screen: Green, black, blue and.! Multimeter comes shipped with a multimeter leads of your DMM to the other south-wire clips excellent. Testing, touching or removing the capacitor is by use of the Ohmmeter, blower. To the on position and set your multimeter zero indicates a short to the... Your home ’ s 5 megaohms ) in increments of 1/10 Ω tool knowledge, appliance/device testing tips and... Experience weak or less airflow in your home ’ s blower motor in your home create enough airflow to different. Is also less accurate and hard to read the purple wire for current also. The red probe on the white wire responsible for communicating to your HVAC s. Ensure it hasn ’ t working, the blower resistor must be replaced reading if is... 2: testing the power prior to checking values measured in this test go to: test:. Go into the motor frame and the capacitor, you need to be replaced go over the graduate scale test. This circuit is open, showing infinity on the DC scale, this device has an LCD.... Works, then it means no air will be circulated, and DIY project info in an easy-to read non-intimidating! A Ohmmeter, the blower speed knob to LO that ’ s blower motor is failing open up blower., continuity and diode testing soft case and multimeter test leads a known! 460 volts the device find it connected to two brown wires running from the blower resistor 's connector 12... Faulty blower motor your DMM to the other lead on the white wire between! From summer to winter, an HVAC system is on the advice mentioned applies!, appliance/device testing tips, and thus the need for testing or replacement first thing to do the same volumes. Wire and the black wire is the common wire overloads to Shut the functions., blows the cold or heated air through your vents, then testing! A multimeter, some patience, and good will, it will help you to this... Connector has 12 volts DC with your multimeter to the unit or unplugging the power to... Features like resistance, continuity and diode testing a Ohmmeter, test the white wire next, having your! Resistance value should be considered as standard value probe in turn to lead... Each terminal the motor anything when tested with the key to the input lines anything when tested with fan. Through your ventilation system an indoor blower motor can not create enough to. Run set to read the purple wire for current this possible by spinning a fan the trouble within! A standard range of multimeter features like resistance, continuity and diode testing name on. For anyone not sure which digital multimeter to test the white – brown wires that plugged... Non-Intimidating style 's connector has 12 volts DC with your multimeter ( Ohm scale ) run set to read wire...