Common questions

Why does my blower motor only work on high speed?

Why does my blower motor only work on high speed?

Many, many times a car or truck will come into the shop with the customer complaining that their blower motor doesn’t work, or only works on high speed, etc. This is usually the case after a blower resistor failure on one or more speed settings.

Why does my heater not work on high speed?

Heater blower motor will not work on high speed? 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. I remember in older model years of gmc’s and chevys that their was a high speed blower relay that caused this issue.

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.

Why does my GMC heater blower not work?

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. I remember in older model years of gmc’s and chevys that their was a high speed blower relay that caused this issue. If there is a high speed relay, I can’t find it. Any suggestions?

Why does my blower motor only work at slow speed?

Blower motor only working on low speed. Another common symptom of a faulty blower motor resistor is that the blower motor only works at slow-speed. This can be caused because of bad wiring between the blower motor resistor and the blower motor itself.

Why is my blower not working in Hi ( 5 )?

The usual failure of the resistor pack is if it works in HI (5) but not in any other mode or just a few modes. When you switch to high,the blower motor relay coil circuit is grounded and voltage is now applied directly through the relay to the blower motor; bypassing the resistors. So, I would look to see if the relay is ok.

Heater blower motor will not work on high speed? 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. I remember in older model years of gmc’s and chevys that their was a high speed blower relay that caused this issue.

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.

What happens if air handler blows at improper speed?

This could result in liquid refrigerant floodback that would likely cause compressor failure. It is possible that your AC’s air handler blower is functioning at the improper speed, and to maximize its performance, you should make sure that is not the case.

What’s the best speed for an AC blower?

Because this process is complicated, working with an expert in AC repair and maintenance is a worthwhile venture. What is the Recommended Speed for Your Blower?

Why is my blower motor only working at high speed?

The first thing that needs to be determined is the type of noise that is present and the possible sources. Rattling or knocking noises while… The blower motor only working on high speed is a common symptom of a failing blower motor resistor; but the fact the radio stopped working at the same time is unusual.

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. I remember in older model years of gmc’s and chevys that their was a high speed blower relay that caused this issue. If there is a high speed relay, I can’t find it. Any suggestions?

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.

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.

Why does my Dodge Ram fan only blow on high?

This feature is not available right now. Please try again later. If your Dodge’s heater or AC fan will only blow on high, or if it intermittently works on low but then stops, it is very likely your heater resistor. A cheap, easy to replace part, that anyone can fix. Loading…

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.

Why is my blower motor on my Dodge truck not working?

Last summer my blower motor stopped working on the slower settings and would only work on the high setting. Then it would come and go on the high setting. Now it doesn’t work at all. I read about the resistor pack on some trucks going out.

This feature is not available right now. Please try again later. If your Dodge’s heater or AC fan will only blow on high, or if it intermittently works on low but then stops, it is very likely your heater resistor. A cheap, easy to replace part, that anyone can fix. Loading…

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.

Can a blower be used for heating and a / C?

Depending on your local conditions, it is possible that heating and a/c can utilize the same blower speed. Too low a speed will cause freezing (no good)in a/c. The temperature rise in heating (difference between supply and return temperatures) must be within specifications.

Why does my blower fan keep shorting out?

To do this, there are resistors built into the unit to control the voltage. If you are not familiar with how electricity works, basically it comes down to this…resistance causes heat. This heat, over the years, can end up burning up and shorting out the blower resistor and associated wiring.

Why is my Delta 88 heater fan not turning on?

My 1999 Olds Delta 88 heater fan switch turns blower on only occasionally and even then the high setting cuts off the fan (if it’s working). Probably a bad blower motor resistor you have there, or possibly a faulty blower motor or switch. The most common thing would be the resistor assembly, as that goes out more often than the other parts.

What to do if your AC or heater is not blowing?

If your Blower Motor for the AC or Heater suddenly stopped blowing, look here first, it might save you several dollars. Situation, we have a friend that owns a 2017 Chevy Trax LT, she is a nurse who works with my wife, single mom and on a single mom budget.

What happens if air handler blower speed is too low?

This is because the evaporator coil will not be able to adequately dehumidify the space in need of cooling. On the other hand, if the blower speed is too low, your evaporator coil is at risk of “freezing.” This could result in liquid refrigerant floodback that would likely cause compressor failure.

Why does my air conditioner and heater stop working?

However, if you’re experiencing problems from the HVAC controls, then it’s possible that the same issue will prevent both your air conditioning and heater from working. For instance, a failed blower motor won’t be able to blow air into the cabin. A failed fan switch will make it impossible to adjust the blower fan speed.

What causes a blower fan to stop working?

For instance, a failed blower motor won’t be able to blow air into the cabin. A failed fan switch will make it impossible to adjust the blower fan speed. There are a number of other potential issues, ranging from a failed relay to a blown fuse to a short in the wiring.

Can you change the speed of an air blower?

Yes you can but we think its just better to know that it can be done whats involved with a simple speed change of your air blower for your furnace air conditioner or heat pump. Ryan from Environmental Heating & air of nc gives you the color codes and speed of those wires.

How can I lower the blower speed of my furnace?

If you want to solve the air noise problem, move the return air filters out of their hallway locations back to the upstream side of the return air duct at the furnace. In terms of heat pumps, running the external blower faster may reduce i2r copper losses and hysteresis iron eddy current losses.

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.

Many, many times a car or truck will come into the shop with the customer complaining that their blower motor doesn’t work, or only works on high speed, etc. This is usually the case after a blower resistor failure on one or more speed settings.

Why is my furnace blower not spinning fast?

If you think your blower is not spinning fast enough you may also have a bad blower motor, or if an ecm motor, the control board may be bad. If its a fixed speed motor and your getting power to it but its not spinning fast enough it could possibly be a bad blower motor.

To do this, there are resistors built into the unit to control the voltage. If you are not familiar with how electricity works, basically it comes down to this…resistance causes heat. This heat, over the years, can end up burning up and shorting out the blower resistor and associated wiring.

What’s the problem with my blower motor fan speeds?

Probably a bad blower motor resistor you have there, or possibly a faulty blower motor or switch. The most common thing would be the resistor assembly, as that goes out more often than the other parts. A quick check with a test light can determine failure. No Heat In My 2000 Chevrolet Malibu – Blower Not…

Why is my F150 heater fan not working?

When a Blower Resistor fails it can fail in many ways. 1 being the fan won’t turn off unless you pull a fuse 2. you may only have one speed as i suffered high or nothing. 3. you have may not have any fan at all. while there is many reasons for this to fail which includes high resistance in the blower motor. Loading…

My 1999 Olds Delta 88 heater fan switch turns blower on only occasionally and even then the high setting cuts off the fan (if it’s working). Probably a bad blower motor resistor you have there, or possibly a faulty blower motor or switch. The most common thing would be the resistor assembly, as that goes out more often than the other parts.

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.

What are the symptoms of a bad blower motor relay?

3. Melted relay. Another more serious symptom of a problem with the blower motor relay is a burned or melted relay. Relays are exposed to high current loads and can sometimes get hot when they develop problems.

Why does blower only work on high only?

A bad blower motor resistor can cause your blower works on high speed only. 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.

Why does the blower fan only work on high speed?

The fan only working on high is normally due to a defective resistor pack. The resistor pack is used for all speeds except for the fan’s highest speed where the resistor pack is bypassed.

Is my blower motor bad?

No air from the vents. No air flow from the vents when the heater or air conditioning is activated is another symptom of a bad blower motor. If the heater blower motor burns out or short circuits, it will not function, and therefore will not be able to produce any airflow for the system. The blower motor will usually have to be replaced in order…

Is there a way to test a blower motor?

Blower Motor Resistor Testing Place one lead of the Ohmmeter on terminal 1 of the resistor. Place the other lead on terminal 2 and check against specifications. Move the lead from terminal 2 to terminal 3 and check this reading against specifications. Move the lead from terminal 3 to terminal 4 and check this reading against specifications.

How do you install a new blower motor?

Installation of the new resistor is just as easy, and has a new harness that plugs into the existing blower motor. Now it gets just a tad more intricate. There can be anywhere from five to seven wires in this system that all have to be cut, stripped and wired into the new connector provided.

Can a new resistor be installed on a blower motor?

A couple screws later and the resistor is out and unplugged from the blower motor. Installation of the new resistor is just as easy, and has a new harness that plugs into the existing blower motor. Now it gets just a tad more intricate.

How many wires are in a blower fan?

There can be anywhere from five to seven wires in this system that all have to be cut, stripped and wired into the new connector provided. Unfortunately, the wire colors are usually pretty basic, so you have to make sure to match up each wire correctly.

What’s the second speed on a dasshboard blower?

This will usually go before the switch which is much more difficult to access inside the dasshboard. Lost 2nd speed. Live with it. 1,3, and 4 speed are sufficient. Blower motor does not work on 1 or 2 speeds. I have yet to attempt repair. I replaced the blower motor resistor but selection 4 (high) don’t work.

Is there a blower motor that does not work?

Blower motor does not work on 1 or 2 speeds. I have yet to attempt repair. I replaced the blower motor resistor but selection 4 (high) don’t work. Motor makes a squealing noise for a few minutes but stops on (3). But still blows. Blower only works on high.

How much does it cost to replace a blower motor?

The HVAC blower motor may stop working at one or more speeds due to a faulty blower motor resistor block. Our technicians recommend to confirm the resistor is at fault by first checking the operation of the switch. The average cost for a Chevrolet S10 Blower Motor Resistor Replacement is between $77 -$88.

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.

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Ruth Doyle