Why Does A Ford Transit Fan Only Work On High? - Motor and clutch

Why Does A Ford Transit Fan Only Work On High?


When you realize that your Ford transit fan is only on high and you can’t control it, then, something is amiss. Most of the time, the reason for is, that the blower motor isn’t working properly.

You need the fan to keep the vehicle cool, especially after a long day, but it can be uncomfortable when it’s turned up too high, and the worst part is that you can’t turn it down. What might have caused the fan to just work on high? All of the explanations will be presented in this post.

A blower motor is a unit that controls the fan in a car’s heating and air conditioning system. It’s usually on the other side of the steering wheel or in the engine compartment, and it’s located inside the dash.

Before the fan is positioned in a one-sided direction, it must have given you some warning signs that you ignored. When the condenser unit’s fan is turned on, it makes sharp noise.

It may be difficult to pinpoint the source of the problem immediately, as a defective capacitor may be the cause of the Ford Transit fan only working on high.Ford Transit

Why does a Ford Transit fan only work at high speed?

If your car’s fan won’t turn because it’s stuck on high, the first thing you should do is check the blower motor resistor. The blower motor resistor is an electrical component used in the heating and air conditioning system of a vehicle.

It is in charge of adjusting the fan speed of the blower motor. The blower motor resistor changes the setting when the fan speed is changed by using the button on the instrument cluster, which alters the speed of the blower motor.

The blower motor resistor is constantly stressed, which might probably result in it malfunctioning. The operation of the complete heating and air conditioning system can be hampered by a faulty blower motor resistor.

Due to the workload of the blower motor resistor, you’re likely to replace it often.

When a blower resistor fails, the highest fan speed is often the only one that continues to operate since it effectively skips the resistor and obtains the most electric power. When the resistor is turned on, it lowers the voltage going to the lower fan speeds, causing the fan not to function effectively.

There are usually warning signals of a faulty blower fan, which must be addressed as soon as possible so that the compressor of the AC is not harmed. Apart from that, the fan will only work at the highest speed.

You won’t feel air coming out of your vents if the fan isn’t working properly, and the coils in your air conditioner freeze up. This could damage the entire cooling system.

Structure of the Ford Transit blower motor

The Ford transit heating, ventilation, and air conditioning (HVAC) system and blower motor are located in the same location. Depending on the engine, some have a single-speed motor, while others have a variable-speed motor.

The difference between these two is that a single-speed motor can only work at one speed. A variable-speed motor can change its speed as needed to create it. Depending on the fan speed, the heater blower motor reduces or increases the volume of air blowing through the dashboard vents.

Location of the Ford Transit Motor

The motor of a Ford Transit is usually found inside the dash, on the opposite side of the steering wheel, or inside the engine compartment on the firewall.

There’s a red line from the battery running into it, which makes it easy to spot. In some Ford transit models, the motor is located close to the gearbox and behind the engine mount.

The blower motor resistor or control module is usually positioned within one of the ducts in the HVAC system, close to the blower motor.

What causes a blower motor to only work on high?

If your blower motor only works on high, you should take it to your mechanic for a thorough examination. When a blower motor resistor fails, the heating fan only functions at the highest speed setting and does not work at lower speeds.

Check for a broken blower motor resistor, which can cause a heater fan to cease working completely. Other factors that can cause the blower motor to only run on high are if the control board, thermostat, or fuses have malfunctioned.

When a blower resistor fails, the highest fan speed is frequently the only one that works since it effectively skips the resistor and receives the greatest amount of voltage.

When the resistor is running effectively, it limits the amount of voltage going to the lower fan speeds, causing the fan to run sluggishly. When one or more of these resistors burn out, you’re usually left with only one heater blower motor speed, which will only work on high.

What is the primary cause of a blower motor that only operates at its highest speed?

In most situations, because there is a problem with the blower motor resistor, the blower motor will only operate at its highest speed. It can only select a high number, no matter how hard you attempt to turn it low.

Three separate high resistance coils make up the resistor block. Because of the coil resistance, the voltage that can travel to the blower motor is reduced.

The fan speed fails when a resistor coil burns out. Since multiple blower motor resistors are designed in series, if one fails, speed one to three can’t work, leaving only speed four to work. In some configurations, a single resistor failure results in a one-speed loss.

Because some cars have a series type of blower motor resistor, depending on the Ford transit you have, your blower may only run on high.

What happens when a blower motor resistor goes bad?

The blower motor resistor is in charge of regulating the fan speed of the blower motor. The blower motor resistor changes the setting when the fan speed is changed through the use of the button on the instrument cluster, which changes the blower motor speed.

For the reason, the fan speed is one of the most often changed settings on an air conditioner, the blower motor resistor is constantly stressed, which might in due course lead it to fail.

The operation of the complete heating and air conditioning system can be hampered by a failed blower motor resistor. The blower motor may become stuck on one fan speed if the resistor fails.

The heating and air conditioning systems may continue to operate at a single speed, but complete functioning will require the replacement of the resistor.

What are the signs of a bad blower motor resistor?

Some signs of a bad blower motor include the following.

  • The blower motor is locked at a single speed.

One of the signs of a faulty blower motor is when the blower motor is fixed only at a single speed. Something isn’t working properly if it’s stuck in one setting.

If the resistor fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may continue to operate at a single speed, but complete functioning will require that you replace the resistor ASAP.

  • The vehicle’s vents aren’t blowing air.

A malfunctioning blower motor resistor can also result in no air coming out of the vents. The blower motor is powered by the blower motor resistor, which can be turned off if it fails or has any faults.

If a blower motor loses power, it will be unable to produce any air pressure, leaving the heating and air conditioning system with no air coming through the vents.

  • Fog/smoke coming out of the vents

The blower motor may be damaged as a result of this. When the blower motor resistor and wires begin to melt, the fan can’t work well, hence smoke coming out from the vents.

From the hood/exhaust system, you might see smoke inside your car. When the temperature near the unit drops below the dew point, water vapour forms in the air and condenses into water droplets, resulting in fog or smoke.

A clogged air filter or a low fan speed can make things worse. If you notice that your car is discharging so much fog or smoke, pull over, and apply the parking brake, and turn off the engine.

Is the blower motor resistor supposed to get hot?

The blower motor resistor will, indeed, become extremely hot, and because the resistor emits heat, it is faster to defrost the windshield at low or medium fan speed.

Additionally, that resistor must be cooled by airflow or it will burn up.

One of the most common causes of blower motor resistor failure is a malfunctioning blower motor pulling too many amps, which can melt wires/plugs and heat resistors, reducing their duration (expiry date).

What does a bad blower motor sound like?

Usually, a bad blower motor produces a sharp noise. If the blower motor is broken, it will constantly produce noise until it is replaced.

It sounds like screeches, signifying that the airflow is insufficient. At this point, the driver should stop the car to spot what the problem is. Whatever the fault is, you should replace it and not repair it.

Can you repair the blower motor and resistor at the same time?

It is not recommended to repair a damaged blower motor; rather, you should replace it. Moreover, when replacing it, you need to replace the resistor at the same time.

The motor that operates the fan in a car’s heating and air conditioning system is known as a blower motor. It’s commonly found on the firewall or the opposite side of the steering wheel.

Even if you think it is still in order, replacing them would make it work effectively as there is no rule that the cause of the fan working only on high could be linked to the resistor.

How much does it cost to replace a blower motor resistor?

The cost varies from country to country. There is no fixed price; it depends on where you are shopping. However, the average cost to replace the blower motor resistor is between $300 to $800. You can check dealerships, or visit online stores such as Amazon or eBay.

Conclusion

Chiefly, a failed blower motor is the reason the Ford transit only works on high. The part that controls the speed of the blower motor is called a blower motor resistor, otherwise known as a blower motor control module.

When the blower motor fails, you must replace it, together with the motor resistor. If it is not working well, locate the motor to see what the problem could be.

The Ford Transit motor is located inside the dash, on the opposite side of the steering wheel, or inside the engine compartment. Sometimes, they can be difficult to find because they’re normally beneath the dashboard on the passenger’s side or below the glove box, near the blower motor.

The most common sign of a failing blower motor resistor is when the heating fan only works at high speeds and not at low speeds. A broken blower motor resistor can cause a heating fan to stop working completely in some vehicles.

Even though having only one fan speed usually indicates a bad blower resistor, there are other things to check for such as the motor resistor, fan switch, and connections to the blower motor to be sure before replacing parts. Additionally, you need to check the fuse, vent, and air conditioning systems.

Note that a faulty heater blower motor will have no effect on the wellbeing of your vehicle. However, you should replace a broken or damaged component to avoid further damages.

In case you can’t locate the blower motor or diagnose why your Ford Transit fan only work on high, drive to a nearby auto repairer shop to fix the problem.

References

https://www.cars.com/articles/why-does-my-air-conditioning-run-at-only-one-speed-1420663031736/

https://www.autoblog.com/2016/01/08/symptoms-of-a-bad-or-failing-heater-blower-motor-resistor/

https://www.cousinsair.com/resources/ac-symptoms/ac-only-works-on-high/

https://ricksfreeautorepairadvice.com/blower-works-on-high-speed-only

https://www.autoblog.com/2016/01/08/symptoms-of-a-bad-or-failing-heater-blower-motor-resistor

https://www.cashcarsbuyer.com/blower-motor-resistor-problems/

https://repairpal.com/estimator/blower-motor-resistor-replacement-cost#:

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