This tutorial will help you test the 2001-2004 Dodge Dakota and Durango blower motor resistor in a step-by-step way. It is responsible for controlling the blower motor’s fan speed. How to test a heater blower motor resistor The heater a/c blower motor in my wife 2000 Acura TL seems to have failed. This can be a bad blower motor resistor or a failed speed switch. I called the dealer and he said there is a warranty on the resistor pack. Basic instructions on how to troubleshoot the heater blower motor of a Saturn S-series. Using a multimeter set on the Ohm scale, use the positive lead and test the black wire. The blower motor resistor adjusts the blower motor's speed. The motor can be seen hanging down close to the passenger kick panel. This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. Your car doesn't have a resistor pack for the front blower motor it uses PWM (Pulse Width Modulation) to control motor speed. From the passenger foot well area, remove the two hex screws used to secure the blower motor resistor. It uses resistance to control the speed of the blower motor. I have no blower at any speed 01 T&C Ltd with ATC. 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. Standard® offers over 700 blower motor resistors as high-quality replacements that match the OE to ensure top performance. The rest of the circuit is the grounding side of the motor. The blower motor is the component responsible for … 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. Then replace the VBC or resistor (whichever you have) and the motor if necessary, and you're all set. The resistor is between the power source and the fan, and allows only the desired amount of power to go to the fan. This bad boy is a breeze to test since it's located under the dash and not that hard to access (unlike the 2000 and earlier Dakota and Durangos which have it … Because the voltage passing through the resistor is adjusted and lowered … (The black wire is usually the negative.) How does the heater blower motor resistor work? Reattach the harness on the box, then secure the box on the motor with the screws. The good news is, dropping the blower motor is easy and can be done in just 30min or so. If not OK, replace the faulty blower motor resistor block. If the motor is pulling a large amount of current (say 20 amps or more) then the motor is on the way out also. At high speed, the resistor is bypassed, and power comes directly from the switch. In this video you'll learn how to find, test, and if need be replace the blower resistor in a 2002 Dodge van. This illustration shows a typical blower resistor, specifications, and test procedures vary between different manufacturers. BM that draws more than 10A is not good and will cause regulators to fail. 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. Part 1 How To Test The Er Motor … The blower motor relay controls the current used to power the blower motor, and is subject to the constant on and off switching. Facebook; Prev Article Next Article . Would it be safe to shunt/jumper/short the blower motor resistor, provided I am content with having the fan on full blast? The other is by bypassing the blower resistor with a jumper wire and thus indirectly testing the blower resistor assembly. The blower motor resistor assembly, on your 3.9L Dodge Dakota, is tasked with reducing the current that the blower motor uses. With an ammeter you could test the current draw with the blower motor on the HIGH position. Part 1 how to test the er motor part 1 how to test the er motor part 1 how to test the er motor how to replace a er fan motor in. Continue checking each resistor in the resistor box. If any of them are bad, you should replace the entire box with a new unit. This is … Check for full airflow at the vents. How To Test Ac Blower Motor Resistor. Test the blower motor relay-if okay Apply direct power from the battery to the blower motor-don't come On-test the blower motor resistor-if okay the last stop will be the HVAC control module/blower … This electrical component is used to control the air conditioning system of a vehicle. A blower motor resistor is an adjustable resistor. So if you didn't have power there, or you didn't have ground there, the next step, we're gonna test the resistor. Log In Sign Up. The heater blower motor is located behind the glove compartment of your vehicle. User account menu • How do I test a blower motor. Press J to jump to the feed. Locate the blower motor. 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. The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. You can see the wiring running from the motor … Good evening, To test the blower motor resistor, unplug the resistor connector. Unplug the blower motor and test for power using the 12-volt test light in the same manner as explained in Step 1. Verify the fan is intact and it spins without much resistance (bearings go bad in these things when they get age on them). How do I test if it’s the motor or the resistor before I buy the part? The blower resistor is connected in series with the blower fan. But for them to honor the warrant they would have to check the resistor pack. It is my understanding that at the highest fan speed, there is 0 ohms resistance upstream of the blower motor. If you find that the fan in your car only works on high, you might well have a broken one. Locate the fuse for the blower motor in the owners/service manual. When the blower motor relay does begin to fail, the vehicle will usually display a few symptoms that alert the driver of a potential problem that should be serviced . To test blower motor, you need car battery and current meter that can go up to 20A. The blower motor relay is the electrical switch that is used to supply the power for the vehicle’s blower motor. This morning I get in the car and no fan. Testing: Access to the relay & blower is from under the dash on the passenger side. A 1/4-inch socket will be needed to remove the screws holding the cover. With that said, failed blower resistor assemblies don't solve all of the possible failures. I recently (3-4 months back) replaced the blower motor resistor in my 2002 325i. What makes this reduction in current (and speed possible) is the three resistor coils that make up the blower resistor … 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. 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. It takes some time to kill them, but with BM drawing >10A, you will get into a syndrome of replacing regulators and this occurs far too often. 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. Blower motor resistor has repeat failures. The front blower speed is controlled by a power transistor not a resistor. Make sure you have power to the dark green wire from the relay to the motor (key on). Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. The less current the blower motor uses, the slower it runs. Here is the information on replacing the resistor: REMOVAL Disconnect and isolate the battery negative cable. The air conditioning and heating controls allow you to switch fan speeds — and the blower motor resistor controls that speed once you select it. Be sure, when testing the resistor, to also check fuses, relays and voltage. How to Troubleshoot a Blower Motor Resistor. If they are then replace the plug and resistor. The blower motor is a D/C electric motor driven by varying current supplied by the blower motor final stage unit. Test the blower to see if it works properly. If so the transistor is contained in the module on the side of the blower motor housing as shown in the diagram below. I'd like to fix it right, of course, but: 1. The blower resistor is one of the many obscure parts in your car. Hereof, how do you troubleshoot a blower motor resistor? If your blower motor fails, replace the blower and resistor together. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. Testing your Chevy Cavalier Blower Motor Resistor. Locate the HVAC blower motor resistor and test it to see if this is the issue. Unplug the front blower motor resistor from the wire harness connector. By doing so, you can save yourself time and headache by ensuring you fix the right part the first time around. The blower motor resistor (or final stage) varies voltage to the blower motor to achieve the desired speed. The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. The resistor is what controls the blower motor speed by restricting electricity through either the … 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. The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack. Just to the left of the blower motor, an electrical connector connected to a flat 1-inch-by-2-inch plate can be seen. That means the resistor & switches are on the ground side that controls the on-off & speed of the motor. Over time, it can eventually wear out . You don't want to have to go back in if one fails later. masuzi 4 years ago No Comments. In order to test the operation of your blower motor resistor, you’ll be measuring the function by reading the internal resistance. Press question mark to learn the rest of the keyboard shortcuts. Is it the front blower motor you are working on? (The rear aux blower does still use a resistor pack). 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