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