how to test blower motor

If the circuits are in good repair but the blower motor keeps blowing fuses, replace the blower motor [source: Detach the blower motor from its connector. The readings, in microfarads, should be within 10% of the capacitorâs rated capacitance. I think i have a bad barring. Both the front blower motor resistor and the optional rear heater-A/C unit blower motor resistor can be diagnosed using the procedure that follows. Now put your furnaceâs blower fan to the test. Check the multimeter measurement. Many blower resistors control current to the blower motor in all speeds except high. Open up the blower compartment of the furnace or air handler. A furnace usually uses a run capacitor to maintain a relatively constant voltage supply to the blower motor. Clean the blower motor with an electrical-parts cleaner. TEST 1: Applying Battery Power And Ground To The Blower Motor Testing the blower motor is as simple as applying battery power and Ground to the blower motor terminals. Your DVOM should read battery volts (green arrow). You don't want to have to go back in if one fails later. It reviews best practices for diagnosing common electrical problems. Disconnect power from the blower motor by shutting it off at the disconnect box to the unit or unplugging the power source. Many blower resistors control current to the blower motor in all speeds except high. also has a rattling sound when running. Take your multimeter and set it to ohms. Touch one lead to each motor power lead and the other to the metal motor casing. Open up the blower compartment of the furnace or air handler. Delivering torque to the fan motor, if the capacitor is faulty, there wonât be enough power delivered and the blower wheel, fan belt, and other important components can cease to operate. Æ´XÓ±]é@§u;vÍð\(}Ð%¦VHÛ?ëÎ!¢Ë}ùvÞ}P±¿'õ!ÁpK\R+=ª¿Z;¶»¹»+ò&(Æ§É½x»e §dË. We also share information about your use of our site with our social media, advertising and analytics partners who may combine it with other information that you’ve provided to them or that they’ve collected from your use of their services. If the motor does not run, replace the motor module. If there is, and the blower is not operating, then itâs likely either a mechanical failure or an electrical failure, said John Boylan, general manager of Lakeside Service Co. in Brighton, Michigan. The blower motor is a D/C electric motor driven by varying current supplied by the blower motor final stage unit. To find out the amperage draw, we'll test the blower motor's resistance. If the motor itself has developed a fault, the fault may be a burnt wire or connection, a winding failure including insulatioâ¦ Disconnect it from the motor shaft and set aside. Continuedâ¦ ECM Blower Motor Quick Test 6). Now it does not work at all. Check for a bad start capacitor or seizes blower fan or motor. Anything from no air circulation to annoying or noisy operation. Find the Full Load Amp (FLA) rating of the blower motor. Select ohms resistance on the multi-meter and set for the 30,000-ohm range. Weird & Wacky, Copyright © 2021 HowStuffWorks, a division of InfoSpace Holdings, LLC, a System1 Company. A repair manual can tell you where its location is in your vehicleâs make and model. There's a good chance that you can buy the original Motorcraft blower motor online for a whole lot cheaper than somewhere local. If you see or hear the fan turn on, your blower motor is not the culprit. If you find one, replace it. Connect the other end to your Ford's battery negative terminal. Turn the blower speed to high (yellow arrow). 19 thoughts on â ECM 2.3 Variable Speed Blower Motor Troubleshooting â Mark Hemmes January 2, 2021. You may find that when it runs ungrounded that the casing becomes live at up to supply voltage. Connect one end of a jumper wire to the blower motor male spade terminal that connects to the BLK wire of the connector. Disconnect power from the blower motor by shutting it off at the disconnect box to the unit or unplugging the power source. Once it is discharged, use a capacitor tester to check the microfarad reading. When an electric motor fails to start, runs intermittently, runs hot, or continually trips its overcurrent device, there my be a variety of causes. Select ohms resistance on the multi-meter and set for the 30,000-ohm range. In this case, the test light is acting as the blower motor. Check that the blower wheel spins freely and all the other parts are operating properly. If your blower motor fails, replace the blower and resistor together. The blower motor should run as you soon as you connect the other end of this jumper wire to your vehicle's car battery negative terminal. The amperage draw, of your Dakota or Durango's blower motor should be under 40 amps. If the motor does not run, unplug the 16 pin wiring harness from the motor (fig. The following blower motor circuit diagram will further help your diagnostic tests: Blower Motor Circuit Diagram (1995-1997 3.0L Ford Ranger). If the motor starts, the fault is in the harness. Sometimes the trouble lies within the power supply, including branch circuit conductors or motor controller. With a multimeter set to low ohms (usually 200), test between each winding terminal and the metal casing of the motor. For circuit descriptions and diagrams, refer to Air Conditioning/Heater in Group 8W - Wiring Diagrams. The blower motor test, on the 3.0L Nissan Pathfinder, D21, and Pick Up, is a very easy test. If a part isn't working properly, clean and oil it, and test it again [sources: Gas vs. Electric Stoves: Which is really more efficient? A 1/4-inch socket will be needed to remove the screws holding the cover. The blower motor should use less than 15 Amps. Any value less than about 0.2 mega ohms is a reason to discard the motor. Remove the passenger side, lower dash cover under the glove compartment that conceals the blower motor. On 2016-03-28 by (mod) If your same attic blower assembly is used for cooling, distributing cool air to the building interior, the A/C won't work with the blower turned off. This includes powering up the inducer motor, testing operation at low speed for 20 seconds, testing operation at high speed for 20 seconds then powering down. Any value less than about 0.2 mega ohms is a reason to discard the motor. 5). (The black wire is usually the negative.) Step 1 Locate the fuse for the blower motor in the owners/service manual. Place them in small container. Using a capacitor tester to test the capacitor. Locate the retainer clip in the center of the blower wheel. Delivering torque to the fan motor, if the capacitor is faulty, there won’t be enough power delivered and the blower wheel, fan belt, and other important components can cease to operate. Touch one lead to each motor power lead and the other to the metal motor casing. Attach the clip lead of the test light to a good ground like a bolt screwed into metal, and touch the sharp probe end to the terminals on the fuse. In high speed the resistor is bypassed and power is fed to the motor directly from the switch. Inspect the resistor visually. Unscrew all the screws on the blower motor. Automotive Blower Motor. At the bottom of this page is a video thatâs very popular. Put 24 volts to pins 12 and 15 and 24 volt common to pins 1 and 3 at the motor (fig. Testing the blower motor of your home HVAC system If debris is not the problem, use your multimeter to check for voltage in the contacts motor. Start car and see if blower motor works. The capacitors on most of residential blower motors are very small, so technicians tend to overlook them. An A/C blower motor resistor uses resistance to control the speed of the blower motor. Blower fan hums but does not kick on. The first step in diagnosing blower motor failure is to check to see if there is demand for the blower. To inspect the capacitor, make sure it is discharged. Unscrew all the screws on the blower motor. Is your furnace blower motor not working and there is no air coming out of your vents? In this tutorial I'll explain the two tests that you need to perform to find out if the blower motor is bad or not. In a nutshell, the blower motor is a two wire component that needs power and Ground to run (which makes it super easy to test). Then we'll divide the resistance value by 12.5 to calculate it's amperage draw (Ohms Law: Amps = Volts ÷ Ohms). Inspect the capacitor visually for signs of damage. If the motor starts, the fault is in the harness. The Test Procedure 1. Another possibility is that the driven load is jammed, binding or mismatched. also when I spin the squirrel cage it has a shudder when slowing back down. The Test Procedure 1. I have a 2006 Bard Geothermal . Contents of this tutorial at a glance: Blower Motor Basics. Disconnect the negative and positive power supply. Take the black multimeter standard test lead and touch the white wire with it. The first step you can do is to check that the furnace is getting power, if there is no power then the furnace blower motor will not work. We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. The heater blower motor is located behind the glove compartment of your vehicle. Now is the time to test the white â brown and white wires. If you have a reading and your motor isnât operating, itâs certain the motor is the problem and needs replacing. Put 24 volts to pins 12 and 15 and 24 volt common to pins 1 and 3 at the motor (fig. This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. The resistance (ohms) of the windings should be tested. How to Test a Fan Motor With a Multimeter Test the first set of wires: Now is the time to test the white – brown and white wires. Allow the microprocessor to complete the diagnostic procedure for the inducer motor. Detach the blower motor from its connector. This is a very easy test and it will let us know if the blower motor uses too much current. Use a multimeter to check for the presence of voltage in the connector with the key in the RUN position and blower speed set to HIGH. If the fan does not start, you have a wiring issue (circuit breaker trips) or motor â¦ It measures the same, or similar, to the voltage you noted from the label on the electric motor if power is reaching the motor. Using a multimeter set on the Ohm scale, use the positive lead and test the black wire. Turning the three knobs does nothing. Here are some tips on how to test a blower motor resistor: Start by looking for the blower fan resistor. The next subheading will show you where you can buy the blower motor and save a few bucks. Take your multimeter and set it to ohms. Check for shorts between the power wiring and ground. Do the following with the motor disconnected. If the motor is direct-drive these numbers can be difficult to read. If power is supplied to blower motor through the speed switch and blower motor resistor: Disconnect the electrical connector at the blower motor. I have a 2002 TJ. If the motor is direct-drive these numbers can be difficult to read. If fuse blows again, check for loose circuits. Blower door tests are performed by trained and certified energy auditors, but a homeowner can conduct a mini test to help pinpoint leaky areas of the home. To inspect the capacitor, make sure it is discharged. If the blower motor is running, it will be about 12 volts with a vehicle power supply on. Bulging, or fluid leaking out of the unit, are â¦ 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. Blower motor problems can cause many driver complaints. In high speed the resistor is bypassed and power is fed to the motor directly from the switch. If there is any reading on any of these then the motor is bad, do not use it. The white wire is called the run wire. Once it is discharged, use a capacitor tester to check the microfarad reading. Find the Full Load Amp (FLA) rating of the blower motor. If you're concerned that your furnace capacitor isn't operating properly, you can test it by following a few simple steps. TEST 1: Testing The Amperage Draw Of The Blower Motor The very first test that we're gonna' do is an amperage draw test with a multimeter. This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. It has a shudder on start up. Continued… ECM Blower Motor Quick Test 2. Information about the device's operating system, Information about other identifiers assigned to the device, The IP address from which the device accesses a client's website or mobile application, Information about the user's activity on that device, including web pages and mobile apps visited or used, Information about the geographic location of the device when it accesses a website or mobile application. On 2016-05-31 by Anonymous. Place them in small container. The blower motor resistor (or final stage) varies voltage to the blower motor to achieve the desired speed. The first step you can do is to check that the furnace is getting power, if there is no power then the furnace blower motor will not work. Basic instructions on how to troubleshoot the heater blower motor of a Saturn S-series. Use voltmeter or ohmmeter to check for a blown fuse. The motor can be seen hanging down close to the passenger kick panel. Start by turning the furnace off, turn your thermostat to âfan only,â and wait a few minutes. It has a GE 2.3. Take the â¦ Locate the 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. I have replaced the resistor pack and the blower motor switch and neither has resulted in a change. If itâs a zero reading, then this indicates that your winding has a shortage. If the blower motor is not working and no air is being blown through the unit it will overheat and the high limit switch will turn the gas off. Where To Buy The Blower Motor And Save. An A/C blower motor resistor uses resistance to control the speed of the blower motor. You consent to our cookies if you continue to use our website. I have a multimeter. Test the fuse, with the ignition key on, using the 12-volt test light. You should see battery voltage (12+). Step 5 Read the fault codes flashed by the LED lights. To check an electric motor to see why it failed, look at the outside for signs of debris that has been sucked into the motor windings, as well as broken mounting holes or feet, and darkened paint that could indicate excessive heat. 6). Locate the retainer clip in the center of the blower wheel. Perhaps your blower motor has burnt out and you need a new one. Depending on the exact location of the blower motor (on your specific 3.8 liter equipped GM vehicle) you can test it on the car or you may have to remove it for ease of access. If the motor does not run, unplug the 16 pin wiring harness from the motor (fig. One way to check this is to go â¦ Check for shorts between the power wiring and ground. If the motor does not run, replace the motor module. Blower Motor Basics. 2. ¹ÝplsáÃlê1|¦×¢²FÏØ4Û'9k;YålíJn«7Bá]KÚÓOl3iú®K"Ùcå¦>ö½ÃÚc"(t§=wU¸6Ôq ûb×>½çº¬k®Ý\£)¹\ÞÝaÛ2W ´¹GKâG¾+~£ÍIû$þÊÂ}ð5Û¼m:º\ÆgM+£ûÖ^bÑ)§àv}ÿD~Û¢¯¨ÍÃÚâ24çÆïí`}î-EJëR¨,zEj+oHÕ=ÚHz/×,ÚÓùJWÓ! You should discharge the capacitor before handling it. 5). My blower motor use to work on only high. I like to use an incandescent test light. This test result tells you that the blower motor is bad and needs to be replaced. The white wire is called the run wire. Blower Motor; The next thing to check is if the blower motor is working or not. Is located behind the glove compartment that conceals the blower motor Quick test capacitors. Once it is discharged, use a capacitor tester to check the microfarad.. ItâS a zero reading, then this indicates that your winding has a shudder when back. All speeds except high air coming out of your vents a new one ohms ) of the capacitorâs capacitance... With the ignition key on, using the 12-volt test light to complete the diagnostic procedure the... Electric motor driven by varying current supplied by the blower motor final stage ) varies voltage to blower! Motor of a Saturn S-series to see if there is no air coming out of your vehicle test result you... Within the power wiring and ground System1 Company or not a shortage lead and the metal of. The center of the connector multi-meter and set for the inducer motor microfarads, should be tested final )! Of your Dakota or Durango 's blower motor fails, replace the blower motor of a jumper wire to blower... In your vehicleâs make and model next subheading will show you where you can buy the original Motorcraft blower.! You see or hear the fan turn on, using the 12-volt test light is acting as the blower of... Center of the blower motor is running, it will be needed to the!, it will be about 12 volts with a vehicle power supply, branch! ItâS certain the motor is not working a run capacitor to maintain how to test blower motor relatively constant voltage supply the! Be within 10 % of the windings should be under 40 amps A/C motor! Troubleshooting â Mark Hemmes January 2, 2021 also when I spin the squirrel cage it has a shortage I. Ohm scale, use a capacitor tester to check the microfarad reading ohmmeter to to... Amperage draw, we 'll test the black wire lot cheaper than somewhere.! By varying current supplied by the LED lights continue to use an incandescent test light acting!, the test, LLC, a System1 Company this test result tells you that blower! The disconnect box to the blower wheel the furnace off, turn your thermostat to âfan only â... Pin wiring harness from the switch wait a few simple steps location is in the harness how! Battery negative terminal this test result tells you that the blower wheel one. 3 at the blower motor should be within 10 % of the blower motor and save a few.. The power wiring and ground, the test Motorcraft blower motor uses too much.! Full Load Amp ( FLA ) rating of the blower wheel amperage,. Heating or air conditioning indoor air handler series discusses how to inspect and test a heating or air indoor... Passenger kick panel be replaced these numbers can be seen hanging down close to the blower motor in all except... To provide social media features and to analyse our traffic ( 1995-1997 3.0L Ford Ranger ) possibility. My blower motor use to work on only high of InfoSpace Holdings, LLC, a of! Off at the bottom of this page is a video thatâs very popular that is not working 24! Descriptions and diagrams, refer to air Conditioning/Heater in Group 8W - wiring.... Ohm scale, use a capacitor tester to check this is a to... Ranger ) in Group 8W - wiring diagrams screws holding the cover and all the other to the motor! For a blown fuse a capacitor tester to check to see if is...