Blower motor problems can cause many driver complaints. no air circulation to annoying or noisy operation. At the bottom of this page is a video that's very popular. practices for diagnosing common electrical problems. Finding the location of the fan assembly is a good place to start diagnosis. The ac blower motor is usually located in the AC duct housing or heater case assembly. This interior fan is always mounted near the evaporator and heaterDepending on the year, make, and model you may find this component both in the interior cabin area or outside in the engineIf it's in the engine bay you'll most often find it near the firewall. You can use the component location diagram in your online service manual to pinpoint the specific location of the squirrel cage (fan blades). can't tell you how often I have found a critter nest in the heater case. Location diagrams will also point out important parts in the climate control system such as relays, switches and fuses.

Be careful, on some vehicles when the engine is running the interior fan is inhow to change fuse for ac unit constant operation at a low speed. ratings on hvac systemsGM called this astro ventilation. carrier rooftop air handling unit provide an ample supply of fresh air in the interior compartment even when no climate control mode is selected. I believe General Motors first used it in the 70s. On vehicles with early climate control systems the fans may not activate until the engine reaches a specificThis is to prevent the circulation of ice-cold air on cold winter days when heat is selected on the climate control.Some drivers and car owners might complain about these normal operatingYou can't fix what is not broken.

Its a good idea to check other like models to determine if there is a problem, or is it just operating as per design intent. Pictured on the right is an interior fan resister assembly from a late 70s GM car or light truck.Special Note: I put together a separate blower motor problems page for Chrysler and Dodge owners. The blower motor resistor assembly is a common malfunction on them. In fact, they sell a harness repair kit for a few bucks that you'll need to fix the issue for good. I also have a page focused on four GM HVAC issues on cars and trucks from the 2000s. resister block used on many models is coupled with a control module. control the output speed of the blower motor. A resister block will adjust its total resistance as selected by the driver from the switch. resistance is applied to the circuit the slower the interior fan motorWhen I diagnose electrical problems, I start at the load and work my way back through the circuit towards the battery.

However, when it comes to the interior fan I will usually go right for the fuse and check thatOften there are two separate circuit fuses and they can be in seperate panels. As an example on GM cars from the 80s and 90s there's a 20 amp under the dash. There's also a 30 amp Maxi fuse in the engine bay convenience center. With the amount of current or amps flowing through this circuit, spikes can easily take out the fuse and damage relays. you do find a burnt fuse continue to test the system and try to find out why it got toasted. Two common reasons for this to happen would be drawing too much amperage or a problem with the resister block mentioned above. I have a dedicated page on how to find electrical shorts if you need more assistance in that area. If you check all the fuses and they're good, the next recommended step is to continue diagnosis by using a test light. an automotive meter to verify good power and grounds at the blowerI often find DIY car mechanics will skip checking the

ground and move right onto parts replacement mode if they find voltage to the fan motors. Remember, you need a good ground to complete theIf the test light reveals no voltage at the fan and my fuse is good, I confirm a solid ground before I move on. Next I'll head to the resister block assembly and check for power coming out of the resisterThese are most often located in the heater case near the blower motor.If your test reveals power going into the resister with a solid ground present and nothing coming out, this is most likely your failedMake sure you check the connector side for damage. These resistor modules often fail from heat stress that can melt plastic connectors. They mount the resister block in the air conditioner or heater case, because of the generous amounts of air flow. That's why they're not far from the squirrel cage itself. They do this for cooling purposes.Nevertheless, often when this component fails, it suffers catastrophic heat damage.

you remove the part you will instantly see that it has melted spots. It could also smell like burnt hair.Fixing your own problems in this system is usually well within the reach of the average do-it-yourself mechanic. diagnostic charts provided in car repair manuals are often very basic and servicing the parts doesn't require any special tools. Watch the example video below. replacement of parts in the blower motor system are some of the easier repairs to perform on the automobile. However, there are a few vehicles out there that make it extremely difficult. You'll have to decide on your own if this is within your skill level.Bookmark this automotive AC blower page or share. : The Source for Professional Diagnostic and Repair Information. Learn how the rest of the climate control system works and discover why interior fans are an important part of theAir Conditioning Service Packages Pep Boys Free A/C Quick Check When it’s a sweltering 97 degrees and sunny, you walk to your car, open the door to be smacked with a gust of heat so intense;

it must be at least 25 degrees hotter than it is outside. You turn on the ignition, immediately your windows go down, the air conditioning is cranked to its lowest setting and you wait for your car to cool… but it doesn’t. Warm air is blowing from your air conditioning vents and the car isn’t getting cooler. Our Pep Boys professional technicians are certified to diagnose and repair many components in your air conditioning system including the A/C compressor, condenser, blower motor, relays, cooling fans and more! The Pep Boys Free A/C Quick Check is designed to quickly determine whether additional diagnostic recommendations are needed or if a simple refrigerant Charge and Go (with top off) will do the trick. FREE*Free Pep Boys A/C Quick Check includes: A/C System Leak Evaluation True or false – detecting a leak in your air conditioning system is an easy task… The answer, surprisingly, is false. Unlike many other automotive fluids, refrigerant evaporates on contact with air making diagnosing a leak based on visual inspection impossible.

Leak evaluations should be performed when your air conditioning system experiences low refrigerant pressure. Pep Boys offers an AC system leak evaluation that addresses your vehicle’s potential leak problem, and provides a host of air conditioning service packages that will provide the solution you require to keep cool! As low as $34.99Pep Boys A/C System Leak Evaluation includes:Pep Boys A/C System EvaluationWhen so many things can go wrong with a system, a thorough evaluation will provide the insights you need to get it up and running again. The Pep Boys A/C System Evaluation includes an in-depth assessment of your air conditioner’s components complete with recommendations to fix them. The A/C System evaluation price will then be credited to the cost of your system repair or recharge service packages. Trust Pep Boys to evaluate your air conditioning system and provide a best in class solution to keep you cool. As low as $39.99The Pep Boys A/C System Evaluation includes:Deluxe A/C Recharge Service Package Designed to bring a leak free air conditioning system back to peak performance, our Deluxe A/C Recharge is the ideal service package for an air conditioning system that needs a boost.

This service package ensures proper A/C system levels through environmentally safe recovery and recharging to proper specifications. No one helps you keep your cool like us! As low as $99.99The Pep Boys Deluxe A/C Recharge Service Package includes:Deluxe A/C Recharge Service Package with Leak Test When it comes to the performance of your vehicle’s air conditioning system, refrigerant levels are integral. Losing refrigerant volume to leaks in your system can lead to the entrance of moisture and contaminants. Removing these contaminants will prolong the life and efficiency of your air conditioning system. Designed to bring a inefficient air conditioning system back to original performance, our Deluxe A/C Recharge service ensures proper air conditioning system levels through fluid recovery, evacuation, recharging and more. As low as $139.99**The Pep Boys Deluxe A/C Recharge Service Package includes:Pep Boys MiST In-Car Air Quality Service Package Keeping a spotless car is an important step in keeping the quality of the air you breathe better, but what is hiding in your ventilation system could pose a serious problem.

Organisms that love cold and damp places, like mold, mildew, bacteria and other allergens can breed in your vehicle’s vents. When the fan is turned on, these micro-organisms are literally blown into the passenger compartment of your vehicle for you to breathe. Cleaning your interior surfaces and regularly changing your cabin air filter will help this issue… But if you could see what you were breathing, you’d MiST right away. Pep Boys offers the MiST In-Car Air Quality Service Package, a quick service that treats the mold, mildew and bacteria that could be hiding in your vehicle’s ventilation system. As low as $59.99**Pep Boys MiST In-Car Air Quality Service package includes: * Not available in the state of California ** Plus the cost of refrigerant *** Servicing a hybrid vehicle usually requires removal of trunk access panel for power supply access, shut off and reconnectionA shop supply fee will be an additional charge (except in NY and CA) of 9.99% up to $35.00. Each individual work order will identify and apply any applicable shop supply charge.