Why does my furnace blower turn on and off constantly?

The system uses a “temperature probe” to detect temperature changes inside the heat exchanger (see image below) and turns your blower on and off in response.

So if your furnace blower is turning on and off when the furnace isn't in a heat cycle, it usually means the fan limit switch is defective.

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Why does my furnace turn on and off repeatedly?

Why a Clogged Furnace Air Filter Can Cause Your Furnace to Turn On and Off Repeatedly.If you remember from our orientation up above, the most common cause for your furnace to keep turning on and off is the High-Limit Switch, which turns the unit off if the temperature inside gets too high (as a s...

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Why does my furnace turn on when the heat is off?

This is most common cause of short cycling.A dirty air filter restricts air from getting into your furnace.Your furnace's heat exchanger needs that air blowing over it or it overheats, causing the furnace to shut down.Change (or wash, if you have a washable type) your air filter if it's dirty.

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Why the overdrive light turn on and off constantly?

Your overdrive light could be faulty. You should check your fused and replace the one associated with the overdraft button.

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Why is my furnace fan not turning off?

The fan control should be set to AUTO.You can try turning the switch to OFF too.Other snafus such as a shorted thermostat wire can also cause the A/C or warm air furnace fan to run continuously.Those problems are explained at THERMOSTAT WON'T TURN OFF.

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Why does my Car radio turn off and on?

The wires are proboly came loose or something.

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Why does my AC keep turning on and off?

Oh, the dirty air filter.It's the cause of most AC malfunctions and understandably so.A dirty filter restricts airflow and restricted airflow causes a whole slew of problems, including a frozen evaporator coil.This can cause the unit to malfunction by turning on and off in short bursts.

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Why does my AC Fan keep turning on and off?

Oh, the dirty air filter.It's the cause of most AC malfunctions and understandably so.A dirty filter restricts airflow and restricted airflow causes a whole slew of problems, including a frozen evaporator coil.This can cause the unit to malfunction by turning on and off in short bursts.

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Why does my car radio keep turning off and on?

When a car stereo cuts out and then turns back on: The problem is usually in the wiring.If the display shuts off at the same time the music cuts out, then the unit is probably losing power.Tracking down the fault can be difficult when the radio is functioning, since it actually has power at that ...

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Why does my HVAC turn on and off?

Oh, the dirty air filter.It's the cause of most AC malfunctions and understandably so.A dirty filter restricts airflow and restricted airflow causes a whole slew of problems, including a frozen evaporator coil.This can cause the unit to malfunction by turning on and off in short bursts.

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Why does my AC compressor turn on and off?

Short cycling, when the compressor constantly shuts on and off, is one of the most common air conditioning problems.Several conditions cause short cycling, including a faulty or obstructed thermostat, leaking refrigerant, icy coils or an HVAC system that is too big for the building in which it is...

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Why does my heat keep turning on and off?

#1: A dirty air filter The first (and most common) cause of short cycling furnace is a dirty air filter.A dirty filter restricts air from reaching your furnace's heat exchanger, which causes your furnace to overheat and then shut down.Eventually it will turn back on and the process will repeat i...

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Why turning my ignition on and wont turn off?

Turning my ignition on and wont turn off because it is faulty.

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Why does my furnace make a loud noise when it turns on?

This can sometimes create booming or banging sounds when your air handler turns on and the pressure changes inside of your ducts.If this sound gets louder or occurs more frequently than usual, it's likely due to pressure buildup in your ducts that are caused by a clogged air filter or closed vent...

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Why does my blower only operate on 3 and 4?

My first guess would be the blower motor resister. My second guess would be the switch and or plug into the back of the switch.

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Why does my car start and then turn off?

An issue with the mass airflow sensor may manifest itself when a car starts and then stalls soon after starting.When an ignition coil begins to fail, it may struggle to provide consistent spark to the plugs, causing the engine to stall after starting.

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How do I make my furnace blower quieter?

reduce furnace noise: how to quiet a noisy furnace Fix the weak spots. If the ductwork in your furnace is faulty, the furnace will produce a banging sound because of the oil-canning. Fix the gas ignition problem. Replace dirty filters. Fill the gaps in the ducts. Resize your air ducts. F...

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Why is my furnace running when thermostat is off?

Set your thermostat to a temperature that's lower than the current room temperature.This shuts the furnace down and prevents your thermostat from calling for more heat.If so, it's likely that you've set your set temperature too high, causing your furnace to heat continuously as it tries to reach ...

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Why does my car air conditioner compressor turn on and off?

Short cycling, when the compressor constantly shuts on and off, is one of the most common air conditioning problems.Several conditions cause short cycling, including a faulty or obstructed thermostat, leaking refrigerant, icy coils or an HVAC system that is too big for the building in which it is...

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Why are my brakelights constantly on when I turn my ignition on?

Check the operation and alignment of the stop light switch

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Why does my car keep turning off?

Another reason that makes your car shuts off while driving is issues with the fuel pump.If there is something clogging in the pump or filter, it will make your car turns off while driving on the roads suddenly.So, it is always mandatory to check and clean the fuel pump, filter before driving a lo...

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Why does my thermostat not turn off?

Step 1: Check the Thermostat If an air conditioner does not automatically switch off, it may be because the temperature has been set too low.This action tells the air conditioner system to switch off.If the unit does not immediately turn off, then it is likely that the thermostat is not the prob...

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Why does my car suddenly turn off?

Your car shuts off while driving suddenly may cause from the ignition switch.When the ignition switch is frazzled, this will lead to a loss or power to your engine due to vibration such as hitting a round patch of street.

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Why does the warning lights come on after starting and blower motor temp tach radio come on and off randomly on my 1997 Pontiac Sunfire?

Main ground for dash is loose.

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Do you have to turn off furnace to change filter?

To Change Your Home Air Filter, You'll Need To Turn Off Your Furnace.To prevent the HVAC unit from turning on while you are changing the filter, make sure you turn the thermostat to the “off” position.For maximum safety, disconnect power from your furnace system while you are doing maintenance.

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My speedometer does not work when I turn on my air conditioner or if you turn off my heat why?

It seems as if there is a problem with the wiring between your speedometer and AC/heat unit. A licensed repairman can determine and fix the cause of this problem.

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What do you do when your furnace won't turn off?

A furnace could potentially not turn off for a few different reasons. Replace your "furnace limit switch." Check the wiring to your furnace's thermostat. Check to make sure none of the controls or buttons on your furnace are sticking in the "Down" position.

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Why is my car shaking and turning off?

Shaking or vibration may be caused by many different things such as faulty spark plugs, poor fuel pressure or misfires.Other things such as a faulty idle air control valve may cause the engine idle to drop below the normal idling RPM which may also cause the motor to shake or vibrate more than no...

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Why does my airbag light keep coming on and off?

Every time you turn on the car, the computer in the vehicle checks the system.The light comes on for a few seconds and then goes off to show that it's working.If it remains on, then there's a problem with the system, and the airbag may not deploy in an accident.You'll need to reset the airbag lig...

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Why does my heat keep kicking on and off?

This is most common cause of short cycling.A dirty air filter restricts air from getting into your furnace.Your furnace's heat exchanger needs that air blowing over it or it overheats, causing the furnace to shut down.Change (or wash, if you have a washable type) your air filter if it's dirty.

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Why does my oil light keep coming on and off?

Low pressure means there either isn't enough oil in the system or the oil pump isn't circulating enough oil to keep the critical bearing and friction surfaces lubricated.If the light comes on while at speed, do your best to pull off the road quickly, turn the engine off, and investigate the probl...

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Why does my blower motor not work on high?

In a situation where the motor doesn't work on any speed, the most likely causes are: a blown power supply fuse, a bad motor ground connection, bad motor speed control module or a failed motor.On all systems, a failed blower motor is least likely.Blower motors generally don't fail out of the clea...

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Why does my blower only work on high?

Most car manufacturers use a series of resistors to make the heater blower motor run at different speeds.And when one or more of these resistors burn out, you're usually left with only one heater blower motor speed—high.The resistor module is easy and inexpensive to replace.

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Why does car turn off when I turn on AC?

It may be from low power to the computer, a faulty fuel pump due to bad connection, or a low battery.The blower fan draws a lot of current, perhaps that is dropping the voltage suddenly and causing some electrical component in the ignition system or the anti theft system to shut down the car.The ...

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Why does my Car turn off after going over bumps?

You may have a lose carbi and it would be sucking too much air and the mixture would be wrong.

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Why does my car smoke after turning off?

This is being caused by some fluid on the engine. You could have an oil leak somewhere and that is what is causing it to smoke only when the car gets turned off.

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Why does my car turn off at red lights?

If your car stalls out at red lights, it means that your engine suddenly can't control the idle.When your engine loses the ability to control the idle, this could be due to several factors, including the following: A malfunctioning or dirty mass air flow sensor.

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Why does my engine run after I turn it off?

When your engine keeps running after shutting it off, you'll hear it firing or coughing.This condition is also known as after-running or dieseling because combustion of the air-fuel mixture happens without the presence of the spark, just like in a diesel engine.

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Why Blower motor wont turn on or stay on?

Common causes, blower motor resistor, blower motor, wiring or controls

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Why does my car turn over and run then shut off?

Useless amount of detail ! - At least tell us the make , model and year if you expect us to find an answer .

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Why does my furnace filter gets black really quick?

So, you're changing your gas furnace's filter and notice that it's got nasty black sooty substance on it.Gas-fired furnaces shouldn't produce soot.And, when left alone, soot can cause pricey problems like: Insulating the heat exchanger, lowering your furnace's efficiency as a result (meaning bigg...

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Why does my car radio not turn off?

Some car radios are on a timer, so they are designed to not shut off immediately.If the radio turns off after a few minutes, that's normal for your vehicle.If it still hasn't turned off, check if the dome lights turn off when the doors are shut.If the dome lights don't turn off, you might have a ...

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Why does my car start then turn off?

An issue with the mass airflow sensor may manifest itself when a car starts and then stalls soon after starting.When an ignition coil begins to fail, it may struggle to provide consistent spark to the plugs, causing the engine to stall after starting.

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Why does my car stereo suddenly turn off?

Fault in the wiring, loose harness pins, or bad head unit is what I'd be looking for.

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Why does my subwoofer pop when I turn it off?

The other pop is caused by the actual switch turning off.There is energy stored in the woofer (inductor) or in the capacitors of the amplifier, which causes a back-EMF when the circuit is cut, much like when you turn off a fluorescent light; sometimes you see a spark at the switch.

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Why does my Mitsubishi eclipse turn off a stop lights?

NOT SURE BUT YOU CAN TAKE IT TO ADVANCED AUTO PARTS AND THEY'LL CHECK IT ON A COMPUTER FOR FREE.

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Why does my car turn off while it is running?

Because there's something wrong with it. For a more detailed answer, take it to a mechanic.

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Why does my car turn off when I stop accelerating?

Common reasons for this to happen: Let's have a look at some of the more common causes that would make your car stall or stumble when you attempt to accelerate.Faulty ignition components: The ignition coil pulls power from the battery and delivers it to the spark plugs, which ignites the fuel and...

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Why does my car sputter after I turn it off?

Usually it's a sign of one or more of the following: (1) excessive gasoline remains inside the combustion chamber even after shutoff, causing "auto-ignition" (similar to dieseling due to compression ignition) even after you turn off your engine.(3) air filter is a bit clogged, causing the carb to...

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Why does my car waste more gas than usual and turn off while im driving?

Could be many reasons, I would start with a complete tune up.

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Why do my car lights turn on and off by themselves?

Hello, thank you for writing in.The vehicle may be having issues with the headlight circuitry.This may mean that the sensor, photocell, body control module, replacement headlight, or a fuse/relay has failed.Something is allowing power to be sent to the headlights when the vehicle should be off.

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Why does my car light not turn off?

The likely cause of a dome light not turning off is either the dashboard light control knob being activated accidentally or a broken door switch.You can remove the wire from the door switch, if you are able to access the backside of the switch.The wire pulls off of the switch easily.

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Why does my car sputter when I turn it off?

Usually it's a sign of one or more of the following: (1) excessive gasoline remains inside the combustion chamber even after shutoff, causing "auto-ignition" (similar to dieseling due to compression ignition) even after you turn off your engine.(3) air filter is a bit clogged, causing the carb to...

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Why is my furnace filter dirty?

Your filter gets clogged faster when your furnace is running more often.That's because more air is cycled through your filter when your furnace goes through more heating cycles, so more contaminants get caught on the filter's media.The colder it gets outside, the faster your filter will get clogg...

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Why after replacing my battery does it shut off when i turn the ac on?

t is probable that your wires are not properly grounded. Check the wiring and ensure that they are properly grounded. Antolin Andrew Marks.

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Why doesn't the blower motor turn on at all?

Are you referring to the air conditioner fan motor or the engine cooling fan motor? In either case you will need to check your fuses first. Then check for power and ground circuits.

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Why ac heater blower motor will not turn on?

Either a bad connection or just clearly a bad motor. They are cheap. But before you go out and get a new or used one hit it a couple times and see if it will come on

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Why does my car turn off when the AC is on?

It may be from low power to the computer, a faulty fuel pump due to bad connection, or a low battery.The blower fan draws a lot of current, perhaps that is dropping the voltage suddenly and causing some electrical component in the ignition system or the anti theft system to shut down the car.The ...

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Why would a car start drivin and then turn off and wont turn back on?

suspect bad fuel filter first, then fuel pump, alternator or battery, ignition module...

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Why does my car don't turn on?

Your battery is probably dead.

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Why can't I turn my headlights off?

In that case, you can try setting the parking brake to see if that shuts the headlights off, as setting the parking brake typically disables daytime running lights.If a bad headlight relay is a reason that your headlights won't turn off, then the fix there is also to just replace the relay.

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Why won't my headlights turn off?

In that case, you can try setting the parking brake to see if that shuts the headlights off, as setting the parking brake typically disables daytime running lights.If a bad headlight relay is a reason that your headlights won't turn off, then the fix there is also to just replace the relay.

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Why did my car suddenly turn off?

Alternator Problems If your car suddenly stops running, it is possible that the alternator has gone bad.A faulty alternator will cut power supply to vital car components and you will notice the lights turning off in the dash or the engine abruptly losing power.

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Why wont my wipers turn off?

First remove the wiper fuse from the fuse box or remove the battery cables.Then replace the wiper selection switch.The switch is stuck in the on position and will not release.If you need further assistance with your wipers staying on, then seek out a professional, such as one from Your Mechanic, ...

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Why will my heater not turn off?

Other mechanical issues can also cause the heater to remain turned on.A defective check valve.For radiators and other heating systems that rely on hot water, a bad check valve can cause the heater to stay on.Without a working check valve, water circulates on its own to keep the heating system tur...

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Why won't my headlights turn off when my car is off on my 1996 subaru legacy outback?

Do you mean the parking lights? if it's the parking lights that are on, check the switch on top of the steering column.

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Why are my headlights not turning off?

In that case, you can try setting the parking brake to see if that shuts the headlights off, as setting the parking brake typically disables daytime running lights.If a bad headlight relay is a reason that your headlights won't turn off, then the fix there is also to just replace the relay.

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Why does my car constantly stall after being warmed up?

OK, heres the deal, i got a magna tr. Starts fine when cold, and runs fine aswell. Revs up easy with no roughness. Drive around till temp reaches normal, and car dies whenever not in gear something to do with idle i reckon. plz help me out... its driving me crazy

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Why does your air conditioner in your s10 turn on and off?

Probably low on charge. You can recharge the system but keep in mind you may have a leak somewhere.

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Why does blower for heat make noise when you turn it on?

Check that there are no leaves or debris in the vents on the OUTSIDE of the car where the air comes into the car (usually there by window wiper mechanism) and Check POLIN filter is not blocked.

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Why does the fan in your 6.0 diesel keep turning on and off?

Thermostatic control to cool engine.

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Does turning LED lights on and off shorten their life?

LED Lighting The operating life of a light emitting diode (LED) is unaffected by turning it on and off.While lifetime is reduced for fluorescent lamps the more often they are switched on and off, there is no negative effect on LED lifetime.

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Why does an engine run on after turning off key?

I had the same problem with my 1967 impala. It was the ignition. There where melted wires. so it would not shut off. That would be the cheapest and first place I would look at. it would start but not shut off.

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Why wont my lights turn off in my car?

The likely cause of a dome light not turning off is either the dashboard light control knob being activated accidentally or a broken door switch.You can remove the wire from the door switch, if you are able to access the backside of the switch.The wire pulls off of the switch easily.

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Why does my check engine light comes on and off on 1991 Honda Accord?

You check engine light is signaling to you that there is something wrong with you car. You should have your car looked at by a professional.

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Why did car just turn off and won't turn on again?

Could be many reasons, charging system failure, fuel delivery failure, ignition failure to name a few.

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Why does the indicator stay on and not flash on and off on my mini city e reg?

your flasher relay is malfunctioning.

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Why does the brake lights stay on after you turn the headlights on and off on your ford?

I dont know because i dont have a FORD Check your brake light switch on the back of your brake pedal for adjustment.

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Why does my car only turns off when gas needle goes crazy and drops all the way down to empty?

Multiple problems could contribute but I would need more details such as does it turn off on it's own or when you turn it off the needle jumps then the car stops running.

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Why does my car start and then shut off?

An issue with the mass airflow sensor may manifest itself when a car starts and then stalls soon after starting.When an ignition coil begins to fail, it may struggle to provide consistent spark to the plugs, causing the engine to stall after starting.

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Why do my headlights flicker on and off?

There are several factors that can cause headlights to flicker while driving.The more common problems could be related to the headlight bulbs themselves, a weak battery, or even the alternator starting to fail.

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When I turn my AC on my car shuts off?

It may be from low power to the computer, a faulty fuel pump due to bad connection, or a low battery.The blower fan draws a lot of current, perhaps that is dropping the voltage suddenly and causing some electrical component in the ignition system or the anti theft system to shut down the car.The ...

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Why does my blower motor resistor keep burning out?

Trent, one of the biggest reasons for blower motor resistors to have shorten life is actually because of faulty blower motor drawing too many amps, some times melting wires/plugs, heating up resistors shortening their life.Then they buy a aftermarket blower motor and again it keeps burning up.

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Why is my AC clicking on and off?

It's the cause of most AC malfunctions and understandably so.A dirty filter restricts airflow and restricted airflow causes a whole slew of problems, including a frozen evaporator coil.This can cause the unit to malfunction by turning on and off in short bursts.

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Why does my blower motor resistor keeps going out?

Worn blower motor causes repeat blower motor resistor failure.However, other factors can cause the blower motor resistor to fail prematurely.For example.If you've replaced a blower motor resistor and that replacement has failed, it's time to conduct an amperage test on the blower motor.

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Why does your car overheat after car runs to operating temp and then you turn car off and back on?

When you shut off an engine, the water pump stops flowing h20 plus antifreeze through the engine block and radiator. All of that extreme heat settles into the aggregate fluid. This can cause the engine to over heat the fluid and boil over. That is the reason you do not go out and take off the rad...

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Why my Lebaron air conditioning compressor kicks off and on?

Low freon you need to recharge

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Why do my car lights keep blinking on and off?

It is important to keep an eye out for the dashboard lights flickering because if the only symptom is a dead battery, then it could simply be that the battery has outlived its usefulness.The above symptoms could also point toward a blown fuse, bad wiring or a loose belt.

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Why does my engine management light keep coming on and off?

If the fuel tank pressure sensor is unable to provide an accurate reading, it'll usually trigger an engine warning light.One common cause of an air leak into – or out of – the petrol tank, is through a fuel filler cap that doesn't properly seal.

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Why does the vehicle turn on but will then turn off?

Fault with immobiliser, will require recoding of keys, of further diagnosis

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Why does your car turn off when you turn corner?

It shouldn't unless you're turning too sharply. You might be low on gas. There might be something mechanically wrong with your car.

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Why does my ABS trac off and service engine light stay on?

Could be a bad ABS sensor. Needs service/replacement.

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Why does my blower motor stop working in 3rd gear on a 2010 explorer?

The issue may be caused by a faulty blower motor resistor.

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Why does the air conditoner blower go to full blast and not turn of after pressing power on a 2001 chrysler town and country?

If you have auto temp control, the blower motor power module has failed. It does the same job as a blower resistor. It is located behind the glove box.

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Why wont your car turn off when you turn off key and remove it?

That means you need to check the head lights. Suprisingly enough head lights on cars cause most problems. Especially on Fords.

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Why does my belt squeal when I turn on AC?

A loud squeal is produced when the A/C is turned on.This symptom is usually caused by a loose or worn air conditioning compressor belt.This places a load on the engine and the drive belt that rotates the compressor.If the belt is loose or worn the belt can slip on the compressor pulley and emit a...

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Why does my radio turn on but no sound?

Effect Of Amps Or Speaker Wires On Stereo Sound The amp can cause the car stereo not to produce any sound at all.If the fuse of the amp blows out, it could be the reason why you are not getting sound out of your car stereo.A broken wire or a bad connection can also cause sound not to come out of...

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Your car just turned off and its not turning on?

Well, it could b a few things. It could be that your alternator isn't recharging your battery and it just shut off because it doesnt have the charge 2 keep your vehicle running at the level its used to, by using the raido and such, or it could be a problem with combustion. it could be your fuel s...

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Why does my car take a while to turn on?

A drop in pressure can be caused by a faulty regulator or a weak pump, or by a clogged filter or injectors.The ignition system provides a spark to ignite the fuel in the engine.Worn-out spark plugs will have a difficult time igniting the fuel in the engine, which will result in longer cranking time.

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Why does my car shake after I turn it on?

The next time you think that why does my car shake when I turn it on, it could be an engine problem, possibly.Issues in the engine can make the car tremble.Yes, the engine compartment can emit the tremble or the shake.Maybe it's not getting the appropriate amount of air, spark, or fuel to run smo...

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Why won't my back brake lights turn off?

The most likely cause for the brake lights staying on is the brake light switch sticking closed.You can disconnect the plug from the brake light switch at the brake light pedal to see if the lights turn off.If they do, you will need a replacement brake light switch.

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