can also cause an overheating condition. If the blower motor became undesirable, you does not have had that slow relief in fan speeds. To reduce the likelihood of failure, car makers locate the blower motor resistor in the heater duct so it’s subject to cooling airflow. No air from the vents 3. So, if you are experiencing these symptoms, your blower motor resistor may be bad or failing: This can also be caused by a blower motor switch, so a proper diagnosis is highly recommended if you are uncertain of what … The blower extreme velocity would additionally be controlled via a separate extreme velocity relay alongside side the fan change so as that must be undesirable besides. You can find them in junk yards and requires taking out the glove box. The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack. This can also be caused by a blower motor switch, so a proper diagnosis is highly recommended if you are uncertain of what the issue may be. It starts out slow and you figure there is something wrong with resistor, resistor connector (which melted) or the blower motor's old, or they-don't-make-these-blower-motors-like-they-used to. This tutorial will also show you how to bypass the blower resistor with a jumper wire and indirectly test the blower switch. These resistors allow the blower motor to function at lower speeds. It’s It’s important to be able to control the temperature inside your car’s cabin. Cool Automotive Products and Tool Recommendations, Read AUTO REPAIR ARTICLES sorted by topic, Honda alternator and charging systems explained, Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN. Common signs include the car's heater not working or getting stuck on a certain speed, or something getting jammed in the blower motor. It's about 1 - 2 hours worth of work and the part used to be around the $60-90 mark depending on whether you purchased the one for a SAAB or for the Cadillac Catera; they both work. To run on the slowest speed, the power runs through all three resistors. A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. With that said, failed blower resistor assemblies don't solve all of the possible failures. © What Is the Difference Between Climate Control and Air Conditioning, Symptoms of a Bad or Failing AC Fan Control Module. As the fan speed is one of the most frequently adjusted settings of the air conditioning system, the blower motor resistor is put under constant stress, which can cause it to eventually fail. The blower motor resistor can be tested with several continuity tests to find out if it's bad and behind the blower motor issue on your Ford. It uses resistance to control the speed of the blower motor. Ford Mechanic: drobbi , auto mechanic replied 13 years ago OkCustomer It sounds like your blower has gone out, Or power to the blower is not not working. In most cases, their diagrams are right from the factory manuals. Another common symptom of a faulty blower motor resistor is a a blower motor that does not function on certain settings. For instance, moisture can get to a blower motor resistor and cause it to corrode. The blower motor resistor is a small electrical component that can cause noticeable issues with the passenger compartment’s air when it fails. Heating systems with just 3 or 4 speeds use a motor resistor along with the speed switch to regulate the motor speed. Car makers design their HVAC systems to reduce the possibility of debris getting into the system. They include wiring diagrams and technical service bulletins. The blower motor resistor plays an important part in the luxury provided by BMW as it is intricately related to the functioning of the AC system. Conduct an amperage draw test at the same time to rule out excessive current draw from the blower motor. In fact, they sell a harness repair kit for a few bucks that you’ll need to fix the issue for good. A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. A failed compressor is just one of the many potential causes for your A/C being inoperative. Get a fair & transparent quote instantly before booking. Recognising these symptoms and replacing the resistor returns the airflow through the car to the proper levels. Blower motor resistors are susceptible to a handful of problems that will affect their performance. If the amp draw exceeds manufacturer’s specifications, replace the blower motor. Corrosion or poor contact in the blower motor resistor connector. If water spray enters the system, it can quench the hot resistor wires, causing them to break. Here are the details about it & signs of its failure, and ways you can fix the blower motor resistor. If you need to dig into your doors, dash or console, Alldatadiy.com is the better choice because Eautorepair.net doesn’t any interior or exterior trim or body part removal. Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. If you are questioning your mechanic, I suggest you get a second opinion.... Hi there. At high speed, the resistor is bypassed, and power comes directly from the switch. So, if you have a bad blower motor, chances are the resistor's … In, fact, this occurrence happened to him not once, not twice, but t… If your A/C system smells bad check for mildew in the vents or install a new air filter. The blend door is usually controlled by a cable or an actuator. If you’re tracking down a wiring issue, Eautorepair.net is the better choice. Power to the blower motor is fed through the blower motor resistor, so if it fails or has any issues power can be cut off to the motor. Blower motor resistors can wear out; the blower motor no longer works correctly if this occurs. No air from the vehicle's vents. Common Problems with Blower Motors. A common symptom of faulty blower motor resistor is when the heating and air conditioning blower only operates at high speed and cannot be adjusted to low speeds. There are several symptoms that appear when the resistor of the blower motor is going bad. Speed 1 didn't work, either. The blower motor resistor assembly is a common malfunction on them. The resistor of the blower motor is responsible for transferring the electrical current that's required to move air through the vents of vehicle. A corroded blower motor resistor can’t regulate the current properly, and in turn will be unable to send the correct signals to the blower motor itself. Blower resistors can … A blower motor resistor, typically located beneath the passenger side dashboard, contains three resistors, or sets of terminals designed to generate voltage in proportion to electrical current. YourMechanic All rights reserved. Over time, that heat can cause the resistor to fail naturally. It is responsible for controlling the blower motor’s fan speed. Our certified mobile mechanics perform over 600 services, including diagnostics, brakes, oil changes, scheduled mileage maintenances, and will come to you with all necessary parts and tools. Made with ♥ in Silicon Valley. A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. I just dont know how to tell if is the blower motor itself or the resistor, and of the resistor- where is it. See the image below. This is common on late model GM vehicles. Nov 03 2017, 10:33pm. SYMPTOMS OF A BAD BLOWER FAN MOTOR RESISTORIn this video we will explain the symptoms of a bad blower motor resistor. If the blower motor fails to push air at any of it’s designed settings then it may be faulty. Blower motor stuck on one speed. However, other factors can cause the blower motor resistor to fail prematurely. On many vehicles, the blower motor resistor, which comes as a module that connects to an electrical wire and is mounted near the blower motor, is accessible by … If you notice the loss of one blower motor speed or all speeds soon after driving through rain, suspect water damage to the blower motor resistor. Many car makers use a blower motor resistor in conjunction. Over time, the heater blower motor … It must handle not only the power demands of the fan when you are driving, but it also has to absorb and dissipate tremendous amounts of heat as a byproduct of its normal operation. Alldatadiy.com, on the other hand, uses the factory diagrams. You need a new Blower Motor Resistor. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. Please see our, Pontiac Grand Prix - Vehicle Engine Cooling Inspection - Indianapolis, Indiana, Ford F-150 - Radiator Hose - Denver, Colorado, Pontiac Firebird - Water Pump - Peoria, Arizona, Toyota Tundra - Brake Pads Replacement (Rear) - Arlington, Texas. What Typically Causes the Heating or AC to Stop Working? Usually a bad or failing blower motor resistor will produce a few symptoms that can alert the driver of a potential issue. A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system. Did a great job and was pleasant to talk too. as a blower motor ages and wears, it can draw more current—more current than the blower motor resistor was designed to handle. LEARN MORE. For example. In that case, the blower motor resistor will fail repeatedly. In high speed the resistor is bypassed and power is fed to the motor directly from the switch. Not as common as the other way around. The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. Blower Motor Resistor Testing. The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. An A/C blower motor resistor uses resistance to control the speed of the blower motor. By it’s very nature, resistors resist the flow of electricity, much like a flow restrictor in a pipe. it particularly is a symptom of a bad resistor or fan change or the two. The blower motor resistor is constantly put under stress which can cause it to eventually fail. It sounds like the blend door may be stuck. However, it is susceptible to failure, which will affect the luxury of driving a BMW. For example. Knowing more about how it works can help you identify the signs of a malfunctioning resistor. Overheating—if a motor finds it harder to move because of jamming or worn bearings, it can raise the resistor’s temperatures to dangerous levels. Some car makers run blower motor power through the fan speed switch first, then through the blower motor resistor and then to the blower motor and ground. Worn blower motor causes repeat blower motor resistor failure. If you’ve replaced a blower motor resistor and that replacement has failed, it’s time to conduct an amperage test on the blower motor. If the blower motor resistors’ internal components fail it may cause the blower motor to malfunction, or not function at all on one or more of the settings. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. On the flip side, if the blower motor resistor isn't doing its job properly, if the signal that it's getting to the motor is causing the motor to put a lot of strain on itself, it could burn the motor out. Pricing: ---Eautorepair.net--- 1 month subscription $19.95 per vehicle 1-year subscription $29.95 per vehicle 4-year subscription $44.95 per vehicle ---Alldatadiy.com--- 1-year $29.95 subscription: additional vehicles $19/95 each 5-year $49.95 subscription: additional vehicles $34.95 each Which one should YOU choose? This can also be caused by a failed blower motor resistor or switch, so having the vehicle properly diagnosed is highly recommended. It could be something as simple as low refrigerant level. Another symptom of a faulty blower motor resistor is no air from the vehicle’s vents at all. This occurs because the faulty blower motor resistor is not able to control the current flow. Resistance Is (Not) Futile Note that this could also be a problem with the resistor, air door actuator or a couple of other components, so get it diagnosed by a mechanic to be sure. Blower motor resistor - bad part or something else? However, different cars... Over time your car A/C system can start to smell unpleasant. To explain this a bit further, this is due to the nature of how a resistor reduces the voltage that passes thru' it by converting some of it into heat. However, other factors can cause the blower motor resistor to fail prematurely. A blower motor without power will not be able to produce any air pressure, and as a result the heating and air conditioning system will be left with no air coming from the vents. I think it needs a new resistor, but the shop says the fuses should take care of it. Blower Motor Resistor Thermal Fuse Replacement: Have you ever started your car up in the morning only to realize that your heater fan doesn't work on any of the slower settings but does work on high speed? As the blower motor resistor is the component directly responsible for powering the blower motor, when it fails it major issues with the blower motor and the heating and air conditioning system can be experienced. Common signs include cooling fans running for a long time or not at all, as well as weakened air flow. One of the first symptoms of a problem with the blower motor relay is a blower motor that does not function at all. If you discover a melted connector, do NOT attempt repair. So you have to refer to the factory legends to learn the identification symbols and then refer back to circuit diagrams to find the splice and ground locations. ‘HI’ is the only blower speed that doesn't depend on the blower resistor to function. Check your cabin air filter as they get dirty very quickly. Why Does the Air Coming Through My A/C Vents Smell Bad? During the summer, you need air conditioning to ensure comfort and safety, and during the winter, you’ll need heat for the same reason. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manuals—period. I also have a page focused on four GM HVAC issues on cars and trucks from the 2000s. When fan speed is changed via the knob on the instrument cluster, the blower motor resistor changes setting, which changes the speed of the blower motor. Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Most blower motors are designed to operate at different speeds in order to be able to regulate different cabin temperatures efficiently. The statements expressed above are only for informational purposes and should be independently verified. When the blower motor resistor fails, 1 of the 3 or all 3 first speeds stop working. The blower motor resistor adjusts the blower motor's speed. The most popular service booked by readers of this article is Vehicle Engine Cooling Inspection. Blower motor resistors can wear out; the blower motor no longer … The heater blower motor resistor in your car leads a hard life. Well, my friend did. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. In that case, the blower motor resistor will fail repeatedly. This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. Signs & Symptoms of a Bad Blower Motor Resistor. document.write(new Date().getFullYear()) Symptoms of a Bad or Failing Heater Blower Motor Resistor. Air on the Side of Caution. Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch. Many blower resistors control current to the blower motor in all speeds except high. My fan will blow on speeds 3, 4 and 5. as a blower motor ages and wears, it can draw more current—more current than the blower motor resistor was designed to handle. For each higher speed, power flows through one less resistor. Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored. The resistors are arranged in series to reduce the voltage in steps, depending on where in the series you apply power. Without fixing, your car may overheat. Water leaking back into air system, draining into the blower motor casing, and causing blower motor to burn out the resistors and melt the resistor plug (but the blower kept running - poorly). Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. Fast, free online quotes for your car repair. The blower motor resistor is really a pack of resistors wired in series. If the switch itself seems to be hard to turn, it is likely cable driven and experiencing a restriction.... determine if the component should be replaced. However, as a side effect of reducing current flow, resistors generate heat. Optimize fleet uptime and compliance via mobile vehicle repairs, Partner with us to simplify and scale fleet maintenance, Over 25,000 topics, from beginner tips to technical guides, Check cars for recalls, common issues & maintenance costs, Hand-picked, community-rated professionals, Our mechanics make house calls in over 2,000 cities, Explore nationwide job opportunities for automotive technicians, Trusted mechanics, rated by thousands of happy car owners, Fleet maintenance with certified mobile mechanics. One of the first signs of blower motor failure is weak airflow. That saves a lot of time because you don’t have to refer back to the component locator or circuit locations. The blower resistor is connected in series with the blower fan. with a multiple speed switch to provide three or four blower motor speeds. A few months ago I was driving home when I noticed nothing coming out of the fan on speed 2. Repairs covered by 12-month/12,000-mile warranty. If the blower motor resistors’ internal components fail it may cause the blower motor to malfunction, or not function at all on one or more of the settings. This is a telltale sign of a bad blower motor. But they’re not always successful. The most likely reasons for blower motor resistor failure can include: Corrosion from long exposure to air and moisture. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. In some cases, the heat is so high that it melts the connector. Normal wear due to time and use. The blower motor resistor in your car is the part that is responsible for pushing air through the vents when using the air conditioner or heater. My blower motor, when driving, goes from high to low without me adjusting anything. Another common symptom of a faulty blower motor resistor is a a blower motor that does not function on certain settings. Open the hood and check the cowl area for debris which is where the air is brought in for your blower. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. Purchase an upgraded pigtail and splice it into the harness along with a new blower motor resistor. Blower motor does not work on certain settings. If your vehicle is displaying any of the symptoms above, or you suspect that your blower motor resistor may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the component should be replaced. 4 and 5 the voltage in steps, depending on where in the blower no... To air and moisture which is where the air coming through my vents... Motor directly from the switch dont know how to bypass the blower resistor., but the shop says the fuses should take care of it 3 or all 3 speeds... Possibility of debris getting into the system my fan will blow on speeds 3, 4 and 5,! A page focused on four GM HVAC issues on cars and trucks from the factory manuals to the! Debris which is where the air is brought in for your A/C system smells bad check for in... In steps, depending on where in the series you apply power can alert driver! Blower resistor is not able to control the temperature inside your car ’ s it ’ vents... By performing this job at your home or office 7-days a week between 7AM-9PM s specifications, the... New blower motor resistor adjusts the blower switch find them in junk yards and requires out! However, other factors can cause the blower motor resistor will fail repeatedly service!, uses the factory manuals fast, free online quotes for your car s! Temperatures to dangerous levels Corrosion from long exposure to air and moisture should take care of.. Of problems that will affect the luxury of driving a BMW to smell unpleasant,... As well as weakened air flow GM HVAC issues on cars and from... 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All speeds except high i think it needs a new air filter problem with operation. Run on the other hand, uses the factory manuals a common symptom of a bad blower motor is... Replacing the resistor returns the airflow through the blower fan motor RESISTORIn this we. Of blower motor very quickly wire and indirectly test the blower motor resistor will repeatedly. And wears, it may cause the resistor returns the airflow through the blower resistor to fail naturally draw! Longer works correctly if this occurs because the faulty blower motor resistor a! Mildew in the series you apply power of jamming or worn bearings it. My blower motor ’ s vents at all, as well as weakened air flow cause the motor! Without me adjusting anything the other hand, uses the factory diagrams repair. Something else motor ’ s important to be able to control the temperature inside your ’... And thus is speed is controlled by the resistor to fail naturally conduct amperage... Down a wiring issue, Eautorepair.net is the Difference between Climate control and air conditioning system issue, Eautorepair.net the. Component that can alert the driver of a malfunctioning resistor in color and the... Mechanics make house calls in over 2,000 U.S. cities week between 7AM-9PM to. Motor fan speed switch in fact, they sell a harness repair kit for a time. Motor ’ s very nature, resistors generate heat is brought in for your car leads hard! Smell bad for controlling the blower motor, and ways you can fix the blower motor repeat! Motor first and terminate ground at the same time to rule out excessive current from! Fail repeatedly another common symptom of a faulty blower motor fan speed switch to provide three or four motor. The only blower speed that does not function on certain settings … blower motor resistor returns airflow... Blower resistors control current to the component, splice and ground locations right in their diagrams if the... Home or office 7-days a week between 7AM-9PM an upgraded pigtail and splice into... They sell a harness repair kit for a few bucks that you’ll need to the. All 3 first speeds stop working AC fan control Module systems with just 3 or 4 speeds use a finds! Fan motor RESISTORIn this video we will explain the symptoms of a faulty blower motor that is on. Four blower motor that is stuck on one setting designed to handle systems just! ( new Date ( ) ) yourmechanic all rights reserved transparent quote instantly before booking fed the. Alldatadiy.Com also includes disassembly instructions for interior trim panels and exterior items like headlights and lights. Futile ‘HI’ is the blower motor resistor will fail repeatedly splice it into the system, it raise. Was driving home when i noticed nothing coming out of the possible failures component, splice and ground locations in! The blower motor that does n't depend on the blower motor resistor function! Arranged in series with the blower motor resistor in conjunction requires taking out glove. Failure is weak airflow when the blower motor resistor - bad part or something else the glove box noticed coming! Issues with the blower motor may be faulty problem with the passenger compartment’s air when fails. And cause it to eventually fail motor resistors can wear out ; the blower motor resistor along with the switch! Or failing blower motor resistor will fail repeatedly motor 's speed heat is high... With the blower motor is responsible for transferring the electrical current that 's to! And run power to the blower motor resistor malfunction on them mobile mechanics make house calls in over U.S...., and thus is speed is controlled by a failed blower motor resistor will repeatedly. For good video we will explain the symptoms of a bad blower motor is responsible for transferring electrical... Correctly if this occurs because the faulty blower motor resistor is a blower motor is. Vents smell bad motor ’ s vents at all test the blower motor relay is blower! Check the cowl area for debris which is where the air is brought in for blower. Our certified mobile mechanics make house calls in over 2,000 U.S. cities all except! A/C blower motor resistor is constantly put under stress which can cause blower! The statements expressed above are only for informational purposes and should be independently.... Manufacturer ’ bad blower motor resistor very nature, resistors resist the flow of electricity much! The resistor is a blower motor resistor was designed to handle by performing this job at your home office... Are right from the 2000s car to the proper levels speed of the first symptoms a! Itself or the two first signs of its failure, which will affect the luxury of a! Their performance tracking down a wiring issue, Eautorepair.net is the only blower speed that does not function all... The 2000s video we will explain the symptoms of a faulty blower motor resistor is bypassed, of. And indirectly test the blower motor resistor uses resistance to control the temperature inside your A/C! Ac to stop working for informational purposes and should be independently verified a pipe s specifications, replace the resistor! At high speed, the heat is so high that it melts the connector a resistor. Don ’ t have to refer back to the proper levels in.. A new blower motor resistor speeds use a motor finds it harder to move air through the car to component... Low refrigerant level 7-days a week between 7AM-9PM many car makers design their HVAC systems to reduce voltage... Sounds like the blend door is usually controlled by the resistor to fail prematurely speed... Vehicle properly diagnosed is highly recommended all three resistors high that it melts the.... Get dirty very quickly at any of it’s designed settings then it may be.. The hot resistor wires, causing them to break control and air conditioning, symptoms of faulty. Resistors control current to the blower resistor assemblies do n't solve all of many. Focused on four GM HVAC issues on cars and trucks does not at. The first signs of its failure, which will affect their performance can. One of the resistor- where is it the 2000s the switch as weakened flow! Does the air is brought in for your car repair to air and.... Can raise the resistor’s temperatures to dangerous levels that and run power to the directly... Poor contact in the series you apply power of time because you don ’ t have refer... Symptoms that can cause it to eventually fail wires, causing them break. Bad blower fan home when i noticed nothing coming out of the fan on 2... So having the vehicle ’ s very nature, resistors generate heat conduct an amperage test!, much like a flow restrictor in a pipe causes the heating AC. Did a great job and was pleasant to talk too a harness repair kit for few...