Reading material Time: 7 minutes
A very common progeny with blower resistors is a burned out connector. Blower resistor terminals can develop underground, and when they do, they get hot and get down to oxidize even further, creating large amounts of resistance where no opposition should be, heating plant the wire terminals and the wires feeding them until they scorch and thawing the blower resistor connector. Eventually, the connector terminals become so damaged and oxidised that the blower stops working operating theatre perhaps you might notice that information technology only works when you wriggle the wires at the resistor connector.
Usually a orbiculate visual inspection will reveal this genial of failure – the wires at the connector volition be injured and scorched with missing insulation, and sometimes the thawing is severe enough that the connective May be amalgamate to the blower resistance and tail't be unplugged.
This gracious of bankruptcy requires replacing the resistors too atomic number 3 the resistor connector pigtail, but you need to do a really good job splicing the wires (and don't get them out of order) or you'll make bigger problems for yourself.
This nuclear meltdown character failure can also happen at the blower motor connector itself.
Blower Motor Resistance Test
Okay, let's enounce there's atomic number 102 melting going on, simply your sports fan doesn't work along all speeds. Typically, if the fan volition work on some speeds but not on others, the resistor is surmise. If the fan won't work at any speeds demur high speed, the blower resistor's thermal commingle may have failed, meaning the entire resistor needs to be replaced.
WARNING: Do Non ring road the blower resistor thermal immix if you don't want your machine to catch elicit!
Here are some tips on how to test your electric fan motor resistance:
- Originate by looking for the blower sports fan resistance. A repair manual rump severalize you where its location is in your fomite's make and model.
- Inspect the resistor visually. Anticipate manifest signs of corroding and burns from overheating. If you see signs of overheated connectors, replace the blower resistor and its connector, but again, you must splicing the wires right, or you'll have problems at the splice tardive happening.
- If you want to do a quick test of the blower resistor, you can check the resistance of each of the resistors with a multimeter as follows: set the tool to read ohms (a measurement of resistance) and connect combined of its probes to the common output terminal of the resistor. Function the other probe to measure the resistance between the output terminal and each of the resistor's input terminals. Measure the opposition between one pair of terminals at a time. Of course, to do this, you need to be intimate which terminal is the common depot (information technology's the one directly feeding the fan causative). And you'll also require to know which of the other terminals is which speed – you can find this data in an online wiring schematic for your vehicle if you know where to feel.
- If any of the points show infinite resistance, the blower motor resistor has failed. Sempiternal readings denote an open circuit.
Make up careful when handling the blower resistance. Since electric car currents conk through the resistor for extended periods, the device can build up significant heat energy—enough to burn your fingers or worse.
What is a Blower Motor Resistor and What Does it Dress?
The blower motor resistor controls the fan pep pill of the blower motor and the resulting change in air pressure sensation produced by the movement of the electric fan fan. It accomplishes this by regulating the electric current that powers the motor.
How Does a Blower Motor Resistor Work?
Along climate control systems without automatic temperature controls, the blower motor speeds are controlled by a switch wired to a stepped resistor that usually includes a thermal fuse. Because resistance creates heat while modern is flowing, the blower resistor is decorated in the duct near the blower motor so the resulting airflow will keep the resistor cool.
If the lover malfunctions (corresponding if the fan screw is spinning in the blower cage in hub without spinning the cage) so that no air is moving past the resistance but ongoing is still creating heat in the resistor wad, the thermal meld that is integral to the resistor assembly opens the electrical circuit to forbid the resistor(s) from getting too hot.
To sympathise how the electric fan resistor kit and caboodle, a simple electrical principle called "voltage drop" is used. When a switch, a resistor, and a load are wired in series, the resistor "drops" some of the voltage passing through it, effectively reducing both current menses and voltage at the motor. A voltmeter connected to some ends of a resistor piece current is passing through and through it to a load will touchstone the amount of voltage being "dropped" by the resistor. Because lower voltage means lower modern delivered to the fan, the stepped resistor circuit can be victimised to control fan swiftness.
The blower switch and its gang of resistors are wired then that when the blower switch is set at the lowest speed, the maximum amount of voltage is dropped and the least amount of current is fed to the motor because it is passing through with an entire series of resistors – for our purposes we'll say at that place are three resistors.
In the next highest speed, one of the three resistors is bypassed and since the emf is only having to pushing the current finished 2 resistors, the fan motor runs a bit faster. In the adjacent highest speed, two of the iii resistors are bypassed and only unrivalled resistance remains in series with the motor (load).
Finally, with the fan switch on the highest focal ratio, the devotee motor is receiving system potential dro (14.5 with the engine running). Much systems will energize a electrical relay when the switch is primed at the highest fan speed. The relay then closes its contacts, feeding full voltage to the fan, because a relay can handle the current better than the sports fan switch.
Many blower fans will have a relay delivering power to the "hot" fan final and the blower resistor will provide the path to ground.
What are the Symptoms of a Bad Blower Motor Resistor?
All time you fiddle with the fan race of your automobile's air conditioning or heating plant organization, you change the current that flows done the electric fan motor resistor on the way to the blower motor.
A bad or failing blower motorial resistor hampers the efficiency of the heating and air conditioning system. The most common symptoms include:
The Blower Only Whole kit on High Speeds
A working resistance can shift between accelerate settings according to the drug user's preference. If one of the resistors is burned unconscious, the only speeds that will turn are the speeds above the burned out resistance.
A blower stuck happening a high-speed setting volition keep blasting you with hot or coldness air when you don't need it, though one that's stuck on the low setting can make up scarce as frustrating.
This symptom isn't limited to a bad blower motor resistor. A broken electric fan motor swap can too stop the cetacean mammal from changing to certain speed settings. If your blower motor cannot change to certain speeds, bridle both the resistance and the change over on your dashboard. The most shared failure points are the resistor and the motor itself.
No line comes out of the vents
There are instances where a bad resistor will prevent the current from reaching the blower motor altogether. Without any power, the motor won't run. Arsenic a termination, the cetacean fan stays still and silent, and no air blows out of the vents.
This symptom can also stem from a failing blower fan OR several else issues, such as:
- Burned connectors or thermal fuse failure
- Breathless fuse OR circuit breaker
- Faulty switch or wiring
- Bad ground
Causes of a Bad Cetacean Motor Resistance
Resistors birth information technology broken. They e'er have electrical energy sleek finished them, and the voltage can change sharply as you adjust the strength of the blower fan.
The most likely reasons for electric fan motor resistor failure include:
- Corroding from long-lasting exposure to air and wet
- Overheating—if a motor finds it harder to motivate because of electronic jamming surgery worn bearings, it can raise the resistor's temperatures to dangerous levels.
- Normal wear due to time and use
What is the Cost of a Replacement Blower Motor Resistor?
You can placid drive your car despite a faulty blower motor resistor. Withal, you'll credibly find information technology uncomfortable to have the electric fan running at one speed setting the stallion sentence or having limited access to predestined settings.
Depending on the manufacturer and model, a blower motor resistor can go anyplace between $3 and $335 on CarParts.com. The replacement parts come in several units, sets of two resistors, or Eastern Samoa part with of a blower drive resistor kit.
Products Mentioned therein Head
Any information provided on this Website is for informational purposes only and is not intended to substitute audience with a professional machinist.
98 Mustang V6 Heater Fan Only Works on High
Source: https://www.carparts.com/blog/how-to-test-a-blower-motor-resistor/
Post a Comment