• Home
  • What does blower motor relay do in car?

What does blower motor relay do in car?

Author of the blog (work in a car repair shop)
Ask Q

What does blower motor relay do in car?

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.

What does a blower motor relay do?

In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.

What does a bad blower motor relay do?

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.

Is blower motor relay important?

The blower motor relay does more than channel electrical current. Relays are a vital protection against electrical surges. When the relay receives a jolt of strong current or simply cannot manage and distribute its load, it will send excess current into the fuse.

How do I test a blower motor relay?

Connect a test light or multimeter to the ground (black lead). Turn the ignition key to the on position (engine off), and remove the relay. Using the probe, test all terminal sockets in the relay connector. Two of the four should have power.

What does a blower motor relay do?

In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.

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

The blower motor is operated by an electrically operated switch, called a relay. If the relay fails, the motor's fans will not blow conditioned air into your car. Fixing the relay usually costs around $50 to $80. So, if the blower motor relay fails, you could be left sweating or shivering.

What are the symptoms of a bad AC relay?

Common signs include inconsistent cooling, not hearing a click from the compressor turning on, and no cold air.

What happens when blower motor resistor goes out?

If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.

Where is the blower motor relay?

The blower motor relay is generally located in the under-hood fuse box or in the under-dash fuse box. A blown fuse can mimic relay failure. A failed blower motor switch can also give many of the same symptoms.

Is there a fuse that controls the blower motor?

Many vehicles have two fuses for the blower motor, one in the interior fuse block and the other under the hood. The blower motor is usually under the dashboard on the passenger side.

Where is the blower motor relay fuse located?

Under the instrument panel, look under the glove box. On the right side of the fender wall you will find another fuse box. The blower motor fuse is easy to replace.

How can I tell if a relay is bad?

You want to feel and listen for any clicks. If you feel and hear clicks, the relay works on one side – the side with the energizing circuit and coil. However, if there was no sound from the horn, the relay has a problem along the contact circuit.

What happens when blower motor resistor goes out?

If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.

How do I know if my AC relay is bad?

Common signs include inconsistent cooling, not hearing a click from the compressor turning on, and no cold air.

What does a blower motor relay do?

In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.

How do I test a blower motor relay?

Connect a test light or multimeter to the ground (black lead). Turn the ignition key to the on position (engine off), and remove the relay. Using the probe, test all terminal sockets in the relay connector. Two of the four should have power.

Why is my blower not working in my car?

Find the fuse associated with the A/C blower motor. If the blower motor fuse is still in-tact, your problem is located elsewhere. If the fuse is blown, simply replacing the fuse with an identical fuse of the same amperage rating could get your system working again!

How long does it take to replace a blower motor in a car?

How Long Does It Take To Replace A Blower Motor In A Car? It generally takes about 4 hours for an experienced technician to do a blower motor replacement. If you are doing it on your own in your garage with common tools, you can expect the job to take 6 hours or more.

How long does it take to replace a blower motor?

How long does it take to replace a blower motor? Replacing a blower motor takes 2 to 3 hours on average. The blower motor is typically located behind a control board and other furnace parts.

Can you drive with a bad blower motor?

Should you drive with a bad heater blower motor? A bad heater blower motor will not affect the safety of your car, with the possible exception of you not being able to clear the windshield of snow, ice, or condensation if the defrosters don't work.

Can you drive without a blower motor?

Your car's blower motor is not only necessary for the operation of your air conditioner. Without a functioning blower motor your engine runs the risk of overheating.

Can a bad blower motor cause no heat?

Problems with Your Blower Motor or Blower Motor Resistor Without it, there's no circulation of air—hot, cold, or otherwise. The blower motor resistor is the part that controls the fan speed of the blower motor. Both of these components can fail, resulting in the heating system simply not working.

What happens when a relay goes bad?

If the relay fails it will cut off power to fuel pump and ignition system, which will result in a no power, and therefore no start condition. You may find that turning the key may power on the accessories, and may even crank the engine.

What causes a relay to fail?

The two most common failure mechanisms of relays are contamination and mechanical wear of the internal switching elements discussed as follows: a. Contamination is a major cause of early life failures.

How much does it cost to replace a blower motor in a car?

Below you will find two interesting articles on a similar topic 👇

How long does it take to change a car blower motor?

Can a bad blower motor cause no heat?

Tired of looking for a video for your question?

Video Answer below 👇

Were our answers helpful?

Yes No

Thanks so much for your feedback!

Have more questions? Submit a request

FAQ for the last Day

  • Why is my furnace blowing cold air and not turning off?
  • Your furnace may be blowing cold air because the filter is too dirty. A dirty air filter blocks airflow over the furnace's heat exchanger, causing it to overheat. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack.Why is my furnace blowing cold air and won't shut off? The most common blower problem that mak...


  • Why is my car not blowing hot air on heat?
  • The first thing to do if you're having issues with your car heater is to check your engine coolant. Make sure to do this when your engine has cooled down to avoid being burned. If your coolant level is too low, there won't be enough hot liquid in the heater core, resulting in cold air.Faulty Thermostat The bad or failing thermostat in car is one of the most common reasons why your car heater is no...


  • Can you drive a car with no coolant?
  • So, in summation, it is best not to drive your car without coolant. If you discover that you are running low and there is no gas station nearby, then it is recommended that you should call for assistance. Do not continue to drive as you may end up permanently damaging your engine.How long can you run an engine without coolant? However, if you absolutely must start your car without coolant, it can...


  • How often do you need to add coolant?
  • Signs it Needs to Be Changed On average, most automobile manufacturers recommend a coolant flush every 30,000 miles or two years, whichever comes first.If the coolant level is insufficient, you must either add more or replace it. You should check the coolant protection level twice a year, in the spring and fall, and more frequently if you drive in extreme conditions. As needed, add coolant.How oft...


  • How much does it cost for a coolant flush?
  • Is coolant system flush necessary? The simplest way to avoid overheating is to service the system every two years or according to your car manual recommendations. Flushing the coolant and replacing it with fresh fluid every two years or 30,000 miles is a good rule. Are coolant flushes expensive? How Much Does a Coolant Flush Cost? The cost of a coolant flush depends on your vehicle's coolant capac...


  • Why is the heat in my car lukewarm?
  • Your thermostat may be stuck, which can prevent the heater system from warming up sufficiently. If your heater is blowing lukewarm air rather than cold air, this may be the culprit. Air bubbles may be trapped inside of the cooling system, which can cause malfunction. This air must be flushed out by a professional.Why is the heat in my car not getting warm? Low coolant: Whether caused by a leak or...


  • Why is my engine not heating up?
  • The most common reasons for the temperature to remain low include: A thermostat stuck open. A bad engine coolant temperature sensor. A locked fan clutch.If you find that you’ve got a car running hot but not overheating there might be a few reasons: Clogged or damaged radiatorWhy is my engine temp cold? The most common reason your temperature gauge staying on cold is a faulty coolant temperature se...


  • How do I know if my Headgasket is cracked or blown?
  • The most common misdiagnoses symptoms of a blown head gasket are coolant disappearing miraculously or an overheating engine for no apparent reason. If you've got a good understand of the cooling system in your car, then it becomes quickly apparent that these two things combined actually make a lot of sense.The signs of a blown head gasket can be subtle. Here are eight of the most common indication...


Comments

Leave a Comment

how
Email us