Why does my blower fan only work on one speed?

by Lee Sallings. The most common symptom of a faulty blower motor resistor is a blower fan that only works on one speed, usually high. This can be annoying, but troubleshooting is easy. If you start at the blower motor, and check resistance in the circuit, you will find the problem in no time.

Why does my Chevy blower motor not work?

I had a Bad Relay. I got one here https://amzn.to/2PSr6fQ It seems the 88-94Trucks have a different system to control the speeds than the 96-00 OBS style Ch… I had a Bad Relay. I got one here https://amzn.to/2PSr6fQ It seems the 88-94Trucks have a different system to control the speeds than the 96-00 OBS style Ch…

How does a fan clutch work on a Chevy?

How to Test a Fan Clutch on a Chevrolet. A fan clutch is the assembly that your engine cooling fan rides on and that tells the fan when to turn on and off. A central core, which locks and unlocks based on the temperature, allows the fan to spin with the engine crankshaft or freewheel on its own.

Can a bad fan clutch cause an engine to overheat?

A bad fan clutch can leave you without an operational fan, which in turn prevents the proper amount of air to cross through your radiator core. Without enough air over the radiator core, your engine can overheat in a matter of minutes.

Why does my Silverado fan only work on 3 + 4?

I have an 01 Silverado and the fan only works on 3+4, so a solution would be very helpful if anyone knows one, thanks It’s probably a bad blower motor resistor. I would replace the blower motor as well. Usually what happens is the blower motor gets worn bearings/bushings and pulls too many amps, which in turn burns the resistor out.

What causes a blower fan to not work?

When this happens, you may notice that you will not feel anything blowing out of the vents at all. This may also cause the blower motor to work intermittently. A blower fan is connected to the negative battery terminal (also called ground) on one end and to the positive battery terminal through a blower motor resistor on the other end.

Why is my Colorado air conditioner fan not working?

It’s probably a bad blower motor resistor. I would replace the blower motor as well. Usually what happens is the blower motor gets worn bearings/bushings and pulls too many amps, which in turn burns the resistor out. This is a common problem with the Colorados like the one I just got rid of…

Why does my car fan spin when the engine is off?

Fan spins after engine shut-down might indicate a weak clutch. Silicone fluid leaking from the fan clutch would cause this problem. When the engine is off, there are a few things you can do to check the fan clutch: Spin the fan. Electronic types might freewheel, but most fan clutches should spin with a little effort.

What are the symptoms of a failed blower motor resistor?

Blower motor resistor problems. Problems with a blower motor resistor are common in many cars. The most common symptom of a failed blower motor resistor is when the heater fan only runs at high speed and doesn’t work at low speeds.

What kind of blower does not work on high?

1997 GMC C1500 Heater/AC Blower Will Not Work on HIGH. 1997 GMC C1500 Heater/AC blower will not work on HIGH. I have replaced the black BOSCH relay behind the glovebox, the blower RESISTOR and the blower MOTOR and still cannot get the blower to work on HIGH.

Can a broken motor switch stop a blower?

A broken blower motor switch can also stop the blower from changing to certain speed settings. If your blower motor cannot change to certain speeds, check both the resistor and the switch on your dashboard. The most common failure points are the resistor and the motor itself.

Why is my blower motor resistor not working?

CLICK HERE TO RESET YOUR PASSWORD! Help! Fan quit working on all 4 speeds. AC light & recirc light still light up and AC compressor clutch engages when turning fan on in AC mode, but not getting the fan to work. I replaced the blower motor resistor and the control unit with new parts from rockauto (ACDelco).

What to do if your blower fan stops working?

Take glove box out on passenger side. Upper left corner is Blower Fan Knock on it. If it comes on it is going out will need to replace. Blower fan will not come on at all? Check Fuses & Blower Fan? Fuses replaced for blower fan,took blower fan out and tested it and it worked? Well it has to be you climate control panel nothing else to check!

What are the symptoms of a worn out blower motor?

One of the symptoms of a worn out blower motor is that it can intermittently produce a loud screeching noise when running. How to test a blower motor? If the blower motor doesn’t work at all, the blower motor itself must be tested first. Typically it’s done by measuring the voltage at the blower motor connector when it’s turned on.

When does a blower motor start to fail?

In most cases, they start to fail by making a high pitched squeal or screeching noise that indicates the bearing is failing. The squealing noise happens most often in the winter during cold startups and may disappear as the motor heats up.

How is the speed of the blower motor controlled?

The blower resistor is connected in series to the blower fan motor. This means that the current running through the blower motor, and its’ speed is therefore controlled by the resistor value. The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack.

Why is the resistor not working on my blower?

Hi There, The resistor is what controls the speed of the blower motor, not the relay. The blower motor relay supplies power to this motor when you turn the switch to “on” that can sometimes fail. When this happens, you may notice that you will not feel anything blowing out of the vents at all.

Is there a blower resistor on a Ford F100?

Let me know, I’ll fire the old beast up and see if I can find them Blower motor resistor with heater and dealer A/C ( C9AZ-18591-A) is different than with factory installed integral AC and Hi/Low Comfort Vent System ( D3TZ-19706-A ).

What causes a fuse to blow on a blower motor?

If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current from a bad relay will blow the fuse and cut power in order to protect the system.

If there is power indicated on high blower speed, but not low or mid range, the problem is the blower resistor. Test for ground at the blower motor if there is power indicated at all ranges, but the motor does not function.

When do you need a new blower motor?

If you are getting 120 volts to the motor and it is not starting then you have a blower motor problem and either need another new blower motor or a new blower motor run capacitor. If you are not getting voltage to the blower motor out of the control board then you probably need a new control board again.

Why does my furnace blower not come on?

I have an older Maytag furnace that will fire up but the blower motor doesn’t come on, after a minute the the limit switches will turn of the furnace because it will get to hot. I already replaced the motor, the limit switches, and the motor board but I still have the same problem.

Can a blower motor relay be a problem?

One of the first symptoms of a problem with the blower motor relay is a blower motor that does not function at all. As the relay is the switch that supplies current to the blower motor, if it fails internally, then power will be cut off from the blower motor circuit, causing the motor to no longer function or blow any air from the vents.

What to do if your blower motor runs all the time?

If playback doesn’t begin shortly, try restarting your device. Videos you watch may be added to the TV’s watch history and influence TV recommendations. To avoid this, cancel and sign in to YouTube on your computer. A collection of my personal auto repair videos on a variety of car repairing subjects.

Why is my blower fan not working on my Ford F 150?

Blower fan not working – 2004-2014 Ford F-150 and other models. Blower Motor Resistor Replacement If playback doesn’t begin shortly, try restarting your device.

What causes a blower motor to overheat?

Decreased airflow causes the blower motor resistor to overheat and fail. Reduced airflow also causes the blower motor to work harder, draw more current and that can cause repeat blower motor resistor failures. Blower motor is drawing too much power. Check the cabin air filter for clogging.

Why is the blower motor not working on my Ford Explorer?

If continuity is not present where indicated in the test steps above and this lack of continuity coincides with the blower fan speed that’s not working on your Ford Explorer then you’ve found the cause of the problem. Replace the blower switch in the A/C-Heater control panel with a new one to solve the problem.

Why does my Ford Explorer fan keep changing speed?

Share it! The Ford Explorer with automatic climate control may have a problem with frequent fan speed changes when using the heater or air conditioner. Normally, the fan speed changes only to maintain a selected temperature, but when the fan speed changes frequently and needlessly, there is an issue with the fan speed control unit.

What’s the speed of a Ford blower motor?

The end result is that your Ford’s blower motor now runs in M1 speed. Battery power is available on terminal 2 of the blower switch connector (BLK/ORG wire). This battery power is now diverted to terminal 4 (YEL/RED wire) of the blower switch harness connector. In tech speak: circuit 2 and 4 is now considered ‘closed’.

How much does it cost to fix Ford Explorer AC fan?

The average cost for a Ford Explorer AC Diagnosis is between $53 -$67. Learn More Bower runs at random speeds, regardless of temp setting. Sometimes when not on auto, speed set manually, the blower will change speeds on its own.

How can I tell if my blower speed switch is faulty?

Test for power at all the blower speeds by moving the blower speed switch through all positions. A faulty resistor loses power at different positions on the switch. High blower speed has direct power to the motor from the switch. If there is no power indicated on high blower speed, the problem is most likely the switch or the fuse.

What should I do if my blower motor stops?

Replace blower motor. If you have a variable speed blower motor, replace the blower motor speed control module. If you have a three or four speed blower motor, remove the blower motor relay. If the motor stops, replace the relay. Alldatadiy.com and Eautorepair.net are professional-grade shop manuals—period.

Why is my blower motor stuck on one speed?

Blower motor stuck on one speed A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed.

How does the speed of a blower motor work?

This means that the current running through the blower motor, and its’ speed is therefore controlled by the resistor value. The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack.

What happens when a blower motor resistor fails?

The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed.

Why does my Ford PowerStroke blower quit working?

Well the “NEW” blower motor is as weak, or weaker, than the original 13 year old Ford blower. That isn’t the problem. It’s been on the truck for 1 day and it’s going back to RockAuto. Today in the 90 degree heat, it decided to just quit spitting anything out of the vents altogether.

How does a 3 speed blower motor work?

Older style blower motor resistor with exposed resistor elements. The blower motor resistor is what’s responsible for giving you three blower speeds. The resistor block contains three different high resistance coils. Think of these coils like a filament in a light bulb.

What to do if your blower motor only works on high speed?

If your blower only operates on its highest speed, chances are you have the series type of blower motor resistor. This is the most common failure mode. To repair the problem, simply replace the resistor block. It’s usually located in the ductwork (to keep the coils cool) below the glove box.

What is the role of the blower motor switch?

Now to be a bit more specific, to achieve LO or M1 or M2 blower motor speeds… the blower motor switch is the component responsible for rerouting the blower motor’s current through a specific combination of these resistors (within the blower motor resistor assembly). Here’s the breakdown: Current passes thru’ all 3 resistors.

Where are the resistors on a Ford blower motor?

The Ford blower motor resistor assembly, covered by this tutorial, has 3 different resistors in series. The purpose of these resistors is to reduce the amount of the blower motor’s current that’s passing through them (as you’re probably already aware, these resistors are located between the blower motor and ground).

Why does my blower fan only work on one speed?