Easy lifehacks

What happens when the blower motor switch stops working?

What happens when the blower motor switch stops working?

When this happens, one or several of the blower fan speeds stop working. The cool thing is that diagnosing/troubleshooting the blower switch isn’t hard. The following circuit descriptions will help:

Is there a way to test the blower motor switch?

The cool thing is that diagnosing/troubleshooting the blower switch isn’t hard. The following circuit descriptions will help: Chassis Ground. Input From Blower Motor. M2 Speed Output. M1 Speed Output.

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.

When do you need to replace the blower motor relay?

If the blower motor does not function, car fuses are blown, or relays are melting, you may have to replace the car blower motor relay. 1. Blower motor does not function 2. Blown fuses 3. Melted relay The blower motor relay is the electrical switch that is used to supply the power for the vehicle’s blower motor.

What are the symptoms of a bad blower motor relay?

One of the first symptoms of a bad or failing AC blower motor relay is a blown AC blower motor relay circuit fuse. 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.

What is a blower control switch?

The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system.

What is a blower motor control?

The blower motor is the electrical switch on the interior of a vehicle that allows the driver to control the vehicle’s heating and air conditioning system. It is usually built into the the same control panel that houses all of the AC system controls, and is labeled with numbers and symbols to indicate blower fan speed.

What is a blower motor relay?

The blower motor relay is what cuts on the blower to release the cold air into the cabin of the car. When you turn on the switch in your car to activate the air conditioner, the blower relay will turn on and release the power needed to turn on the blower fan. This part of your car is only used when the air conditioner is turned on.

What happens when you change the fuse on a heater blower?

If the fuse is blown, replace it and then try the blower. If the fuse blows right away, your car may have a bad blower motor or some other problem in the system. If the blower works when you change the fuse, you may not be out of the woods yet. When the motor gets old and tired it will draw more current through the wires than a new motor.

What should I do if my heater fan switch is not working?

As long as there are no bare wires exposed, reconnect the battery cable and try running the heater fan to see if there is other diagnostic work to be done. If everything checks out, disconnect the battery again, route the switch back through the hole, and attach it with the nut.

Can a blower switch be replaced in an A / C heater?

Replace the blower switch in the A/C-Heater control panel with a new one to solve the problem. To comparison shop for the blower control switch, take a look at this section here: Where To Buy The Blower Switch And Save. CASE 2: All circuits tested had continuity where indicated in the test steps.

If the fuse is blown, replace it and then try the blower. If the fuse blows right away, your car may have a bad blower motor or some other problem in the system. If the blower works when you change the fuse, you may not be out of the woods yet. When the motor gets old and tired it will draw more current through the wires than a new motor.

As long as there are no bare wires exposed, reconnect the battery cable and try running the heater fan to see if there is other diagnostic work to be done. If everything checks out, disconnect the battery again, route the switch back through the hole, and attach it with the nut.

When to replace a heater blower motor switch or relay?

When the motor gets old and tired it will draw more current through the wires than a new motor. It may still draw enough current to blow the fuse after it runs for a while. In that case, a motor replacement is in order. Step 1: Disconnect the battery. Put on your safety glasses and disconnect the battery at the negative cable.

What causes a bad or failing blower motor relay?

Blown fuses. One of the first symptoms of a bad or failing AC blower motor relay is a blown AC blower motor relay circuit fuse. 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…

What happens to the blower motor in a Ford?

In tech speak: circuit 2 and 3 is now considered ‘open’. The end result is that your Ford’s blower motor now runs in M2 speed. This interruption and diverting of battery power goes on for all of the other blower fan speeds.

Why does my Mercedes-Benz A / C blower run uncontrolled?

But under fault conditions it could fail as ‘always on’ or ‘never on’. Mostly (according to this forum) a failed BR causes the a/c blower to run uncontrolled. Btw your WIS a/c circuit diagram is not identical to mine for W208. However the blower motor/regulator part is the same.

Where is the blower control switch on the dashboard?

The blower control switch on the dashboard controls the circuit flow of the blower motor to adjust the voltage from low, to medium, to medium-high, to high. When on high, the circuit bypasses the blower resistor.

When this happens, one or several of the blower fan speeds stop working. The cool thing is that diagnosing/troubleshooting the blower switch isn’t hard. The following circuit descriptions will help:

In tech speak: circuit 2 and 3 is now considered ‘open’. The end result is that your Ford’s blower motor now runs in M2 speed. This interruption and diverting of battery power goes on for all of the other blower fan speeds.

But under fault conditions it could fail as ‘always on’ or ‘never on’. Mostly (according to this forum) a failed BR causes the a/c blower to run uncontrolled. Btw your WIS a/c circuit diagram is not identical to mine for W208. However the blower motor/regulator part is the same.

Do you have to replace the blower switch?

You don’t have to buy the whole A/C-Heater Control Panel to replace the blower control switch since the switch is removable. If you’re interested in the original Ford Motorcraft blower switch or on an after-market part (and save), the following links will help you comparison shop.

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Ruth Doyle