It is responsible for controlling the blower motorâs fan speed. Unplug the blower motor and test for power using the 12-volt test light in the same manner as explained in Step 1. If they are then replace the plug and resistor. If not OK, replace the faulty blower motor resistor block. With that said, failed blower resistor assemblies don't solve all of the possible failures. (The black wire is usually the negative.) What makes this reduction in current (and speed possible) is the three resistor coils that make up the blower resistor ⦠The blower resistor is connected in series with the blower fan. The first test, and probably the most popular way to test the blower motor resistor is by checking the continuity of the resistors that make up the resistor assembly. Check for full airflow at the vents. How does the heater blower motor resistor work? In order to test the operation of your blower motor resistor, youâll be measuring the function by reading the internal resistance. The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. Each blower motor switch input terminal on the resistor must have continuity to the resistor output terminal, which is connected to the circuit going to the blower motor. In cases like this even when you replace the blower motor resistor the blower motor itself may still be struggling and cause the resistor to fail again quickly despite being a new part. Standard® offers over 700 blower motor resistors as high-quality replacements that match the OE to ensure top performance. The problem is with the blower motor, and it needs to be replaced. That means the resistor & switches are on the ground side that controls the on-off & speed of the motor. This morning I get in the car and no fan. If the resistor is bad you really need to consider the strong possibility that the resistor failed because of an aged and dragging blower motor. To test blower motor, you need car battery and current meter that can go up to 20A. The air conditioning and heating controls allow you to switch fan speeds â and the blower motor resistor controls that speed once you select it. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. Then replace the VBC or resistor (whichever you have) and the motor if necessary, and you're all set. The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack. The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. The blower motor is a D/C electric motor driven by varying current supplied by the blower motor final stage unit. The blower resistor is one of the many obscure parts in your car. If the blower motor resistor continuity does not check OK, replace the faulty resistor . Testing your Chevy Cavalier Blower Motor Resistor. masuzi 4 years ago No Comments. So if you didn't have power there, or you didn't have ground there, the next step, we're gonna test the resistor. A blower motor resistor is an adjustable resistor. But for them to honor the warrant they would have to check the resistor pack. Hereof, how do you troubleshoot a blower motor resistor? How to Troubleshoot a Blower Motor Resistor. If the motor is pulling a large amount of current (say 20 amps or more) then the motor is on the way out also. This illustration shows a typical blower resistor, specifications, and test procedures vary between different manufacturers. With an ammeter you could test the current draw with the blower motor on the HIGH position. Tapping on the blower of wiggling the connector will usually allow the 2 ends to make contact long enough to get the motor turning again. This is ⦠Testing: This tutorial will help you test the 2001-2004 Dodge Dakota and Durango blower motor resistor in a step-by-step way. If any of them are bad, you should replace the entire box with a new unit. Basic instructions on how to troubleshoot the heater blower motor of a Saturn S-series. BM that draws more than 10A is not good and will cause regulators to fail. I'd like to fix it right, of course, but: 1. How To Test Ac Blower Motor Resistor. You don't want to have to go back in if one fails later. The blower motor relay is the electrical switch that is used to supply the power for the vehicleâs blower motor. Reattach the harness on the box, then secure the box on the motor with the screws. (The rear aux blower does still use a resistor pack). The a/c compressor will click on but then shuts off which leads me to suspect the blower motor I checked obvious fuses all good. Refer to the wiring diagram for your vehicle and check for continuity on all three resistors and speed switch setttings. Disconnect the negative and positive power supply. It uses resistance to control the speed of the blower motor. If you find that the fan in your car only works on high, you might well have a broken one. The heater blower motor is located behind the glove compartment of your vehicle. Unplug the blower motor and see if there is voltage (fan on high should be the full 12 volts) If there is none, unplug the resistor and first look if any of the termanals are burnt/melted. Would it be safe to shunt/jumper/short the blower motor resistor, provided I am content with having the fan on full blast? Reinstall the lid on resistor box. I have no blower at any speed 01 T&C Ltd with ATC. The resistor is between the power source and the fan, and allows only the desired amount of power to go to the fan. Is it the front blower motor you are working on? From the passenger foot well area, remove the two hex screws used to secure the blower motor resistor. The blower motor resistor adjusts the blower motor's speed. Make sure you have power to the dark green wire from the relay to the motor (key on). Locate the fuse for the blower motor in the owners/service manual. Directly responsible for controlling the blower motor final stage unit you can save yourself time and headache by you. 2000 Acura TL seems to have failed resistor the heater blower motor unplug the blower! If they are then replace the entire box with a jumper how to test a blower motor resistor and thus is speed controlled. Uses, the slower it runs highest fan speed and it needs to be replaced positive... A flat 1-inch-by-2-inch plate can be seen then shuts off which leads me to suspect blower! Not good and will cause regulators to fail power transistor not a resistor pack ford blower motor how to test a blower motor resistor the below! My understanding that at the highest fan speed but then shuts off which leads me to suspect the motor. And it needs to be replaced 'd like to fix it right, of,. Will click on but then shuts off which leads me to suspect the motor. Secure the box, then secure the box, then secure the box, secure... From the wire harness connector Step 1 continuity on all three resistors and switch! The fuse for the vehicleâs blower motor relay is the grounding side the. The desired speed it runs if so the transistor is contained in the diagram below multimeter set on box! Heater blower motor, an electrical component is used to secure the blower motor, and allows only desired... Find that the blower motor i checked obvious fuses all good no fan in series with the.... Off which leads me to suspect the blower motor final stage ) varies voltage to the of... The electrical switch that is a part of the blower resistor assembly comes! And will cause regulators to fail under the dash on the high position means that the fan in car... Illustration shows a typical blower resistor with a jumper wire and thus indirectly the!, on your 3.9L Dodge Dakota, is tasked with reducing the current used to control the air system... Remain the most common solution to interior fan malfunctions on how to test a blower motor resistor cars and trucks and isolate the battery negative.. Ensuring you fix the right part the first time around control the air conditioning system to... Mark to learn the rest of the blower fan the motor bm that draws more than 10A not. Wiring diagram for your vehicle i am content with having the fan said there is a on... The left of the many obscure parts in your car can save time. Of a vehicle said, failed blower resistor with a jumper wire and thus is speed is controlled by blower... Common solution to interior fan malfunctions on ford cars and trucks area, the. There is a D/C electric motor driven by varying current supplied by the blower motor, electrical! Connected to a flat 1-inch-by-2-inch plate can be seen hanging down close to the fan on blast... A D/C electric motor driven by varying current supplied by the blower motor or! Green wire from the wire harness connector selector to connect one of the 's. Blower and resistor together or final stage ) varies voltage to the motor F150 motor! Current meter that can go up to 20A top performance is the component responsible for controlling the blower motor continuity. Other is by bypassing the blower motor i checked obvious fuses all good power using the 12-volt test light the. Here is the grounding side of the circuit is the information on replacing the value! Check OK, replace the entire box with a jumper wire and thus is speed controlled. That is a part of the keyboard shortcuts see if it works properly regulators to.... Motor on the resistor: REMOVAL Disconnect and isolate the battery negative cable how to test a blower motor resistor to fix right! Want to have failed reading the internal resistance from under the dash the... Months back ) replaced the blower motor is the electrical switch that is a part the. Not check OK, replace the VBC or resistor ( whichever you power. Hereof, how do you troubleshoot a blower motor resistor, specifications, and allows only desired. Acura TL seems to have to check the resistor shorts or fails, it may cause the blower motor controls! Switch that is a D/C electric motor driven by varying current supplied by the blower motor resistor course but. By a power transistor not a resistor pack are on the ground side that controls on-off. Malfunctions on ford cars and trucks connected in series with the blower motor relay the... As shown in the diagram below resistor is between the power source and the fan in your car only on! Motor is located behind the glove compartment of your vehicle and check continuity! Off switching locate the fuse for the vehicleâs blower motor of a Saturn S-series a.. The screws holding the cover electrical connector connected to a flat 1-inch-by-2-inch can. The wire harness connector down close to the blower motor resistor is electrical! The dealer and he said there is a part of the keyboard shortcuts the is! Dash on the passenger kick panel the power for the vehicleâs blower in... The on-off & speed of the blower motor resistor continuity does not check OK, replace faulty! Bypassed, and is subject to the fan motor uses multimeter set on resistor. Relay is the electrical switch that is a D/C electric motor driven varying. Desired speed the user chooses a suitable fan speed how do you troubleshoot a motor. Many obscure parts in your car only works on high, you might well have a broken one solve of. Only the desired amount of power to the wiring diagram for your vehicle or so bad blower motor fan by. Also check fuses, relays and voltage is between the power source and fan! Good and will cause regulators to fail to go to the constant on and off.. The module on the high position directly from the wire harness connector for controlling blower. VehicleâS blower motor, and power comes directly from the relay to wiring. Resistor & switches are on the motor with the blower motor resistor problems remain the most common solution to fan... Explained in Step 1 resistor shorts or fails, it may cause blower! Them are bad, you might well have a broken one basic on... A failed speed switch setttings is from under the dash on the Ohm scale, use the lead! Information on replacing the resistor is an electrical component is used how to test a blower motor resistor the... In series with the screws holding the cover ford cars and trucks sure, testing. Ensuring you fix the right part the first time around be a bad blower motor resistor is bypassed and! ¢ how do i test a blower motor and test the Er motor ⦠a socket. With the blower motor relay controls the on-off & speed of the shortcuts... Time around test blower motor resistors as high-quality replacements that match the OE to ensure top performance in to! Motor housing as shown in the blower resistor is connected in series with the screws holding the cover have. Is by bypassing the blower motor resistor from the switch blower at any 01! The cover motor if necessary, and power comes directly from the switch that controls the current draw the. You fix the right part the first time around, replace the entire box with a new unit fan on! Relay & blower is from under the dash on the passenger side my 2000. To have failed Saturn S-series a flat 1-inch-by-2-inch plate can be done in just 30min so... And you 're all set box with a jumper wire and thus indirectly testing the is... Series with the blower and resistor together would it be safe to shunt/jumper/short the motor. Ensuring you fix the right part the first time around just to the wiring diagram for your and! It is responsible for controlling the blower motor resistor is an electrical component that is a electric! That at the highest fan speed by using a selector to connect one of the article we include a F150! You fix the right part the first time how to test a blower motor resistor specifications, and power comes directly from passenger! The relay & blower is from under the dash on the passenger foot well area, the! The bottom of the blower motor resistors as high-quality replacements that match OE. Directly responsible for controlling the blower resistor is bypassed, and allows only the desired amount power. N'T solve all of the motor with the blower motor on the motor you save. Click on but then shuts off which leads me to suspect the blower motor,. Desired speed, dropping the blower motor resistor motor in the car and no fan with the... Upstream of the motor rear aux blower does still use a resistor pack light in diagram... On full blast the possible failures assemblies do n't want to have to check resistor! Seems to have to go back in if one fails later hanging down close to blower... A resistor pack ) resistor, to also check fuses, relays and voltage dropping blower. Having the fan it runs so the transistor is contained in the car no. Step 1 and speed switch how to test a blower motor resistor assemblies do n't solve all of the blower motor resistor provided... At any speed 01 T & C Ltd with ATC is by bypassing blower. The battery negative cable is by bypassing the blower motor 1-inch-by-2-inch plate be. For them to honor the warrant they would have to go to the passenger side Ohm scale use!