My blower motor won’t turn on when it’s extremely cold 2003 Chevy Trailblazer
My blower motor won't work on extremely cold days. The rear seat blower Does work. When it's not cold the front blower Does work on all speeds. It's just the front blower that won't turn on at extreme cold temps
My car has 120000 miles.
Experienced mechanics share their insights in answering this question :
Hi there – electrical failures when cold are tough problems, because the source is an electrical connection – switch contact, brushes in the motor itself, potentially a blower motor relay – that shrinks and loses connectivity when cold. It expands enough when warmer to conduct current. Crawling around in the cold with a voltmeter is no fun chasing problems like this. I would recommend a heater inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.
How to Identify and Fix Common car Problems ?
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Blower motors are designed to circulate air, so they won`t work if there`s no air to move. You should always check the filters and vents surrounding the blower to make sure that the blower isn`t having a hard time working. Look into your air filter`s housing and check the markings on your filter.
The most common reasons for the radiator cooling fan not turning on in stop and go traffic is the coolant temp sensor (or switch), the fan relay, or the fan motor.
The blower motor resistor is responsible for controlling the blower motor speed. In the past, this was done by varying the voltage supplied to the blower motor. In newer applications, the blower motor resistor is actually a solid state module that sends a varied signal to the blower motor.
The blower motor relay is the electrical switch that is used to supply the power for the vehicle`s blower motor. The blower motor is the component responsible for pushing air through the vents of your vehicle`s heating and air conditioning systems.
Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.
On most modern cars, the cooling fan is controlled by the Engine Control Unit (ECU) which gets a signal from the coolant temperature sensor. If it`s not working, the fan won`t turn on when it needs to, which means the engine might overheat.
An unlikely, but possible, cause is a bad thermostat. Try turning the Fan switch to the “On” position to see if the blower comes on. Watch the video. If the blower operates in the “On” position and does not operate when the air conditioner is running, you may have a bad thermostat.
The ECM Motor
In the simplest terms, an ECM motor lowers the total electrical consumption of an AC or furnace and helps to maintain proper air flow through the system. ECM motors contain a microprocessor, which is the key component of what makes them able to provide higher efficiency.
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.
Some older ECM motors will overheat and even fail when constantly running in over-amped conditions. Newer models are designed to drop airflow but time will tell on how well they will hold up. Other consequences of high static installations include noise at the registers from higher air velocities.
To test a blower motor with a multimeter, first set the multimeter to the “resistance” or “ohms” setting. Then, touch the probes of the multimeter to the terminals on the blower motor. If the resistance reading is infinite, that means there is an open circuit and the blower motor is defective.
The blower resistor is connected in series with the blower fan. This means that the current running through the blower motor, and thus its speed, is controlled by the resistor value.
Mechanical or electrical issues are the two main categories of industrial blower fan failure that can completely stop the fan. Faulty belts, loose pulleys, insufficient power, inadequate wire size, blown fuses, and other issues can occur in these areas.
The engine-ECU <M/T> or engine-A/T-ECU <A/T> controls the fan controller to activate the radiator fan motor and the condenser fan motor.
The cooling fan relay is the relay that controls the engine`s cooling fans. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans.
If your coolant level is a-okay, but your car heater is blowing cold air and your engine is overheating, then you have a clog in your cooling system. Conversely, if your engine temperatures are unrealistically low after a drive, your thermostat is likely the culprit.
Generally speaking, when cool air blows during early morning hours, and then blows warmer as it gets warmer outside, it can be due to a few possible sources. First, and most common is that the AC vent is set to draw air from the outside and not through the cabin.
Your thermostat fan setting controls your HVAC system`s blower. The blower helps circulate cold or hot air throughout your home until the temperature reaches the thermostat setting. ON means that the fan is constantly blowing, even when the desired temperature has been reached.
ECMs are the most efficient FHP motor in the market and are built with an electronic control module and motor and do not use capacitors.
ECMs are a type of DC motor. They are also called DC fan motors, EEM fan motors, and variable speed fan motors. They function using a built-in inverter and a magnet rotor, and as a result, can achieve greater efficiency in air-flow systems than some kinds of AC motors.
There are two different types of blower motors for your forced air system, the PSC (permanent split capacitor) and ECM (electronically commutated motor).
Blower motors are a common component in a home, commercial, and automotive HVAC systems. The blower motor relay is an essential component in a functioning HVAC system.
The blower motor resistor controls the power to the system`s blower motor. When it fails, it can cut off all power to the motor. When the blower motor doesn`t get power, air pressure can`t be produced. You are left with a heater or air conditioner with nothing coming out of the vents.
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.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
My blower motor won’t turn on when it’s extremely cold 2003 Chevy Trailblazer
ANSWER : Hi there – electrical failures when cold are tough problems, because the source is an electrical connection – switch contact, brushes in the motor itself, potentially a blower motor relay – that shrinks and loses connectivity when cold. It expands enough when warmer to conduct current. Crawling around in the cold with a voltmeter is no fun chasing problems like this. I would recommend a heater inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.
Engine turned off but inside of car still on, now engine won’t turn back on.
ANSWER : Hi there. The symptoms you’re describing with your boyfriend’s 2002 Grand Cherokee appear to be related to a broken or worn out ignition switch or relay. The ignition switch on the inside of the steering column is attached to multiple electronic connections that send signals to a relay box; which in turn, sends the signal to the individual components. The issue could be related to the ignition switch, the relay, or any of the components in between. If you want to have the fault pinpointed in person, I would have this starting issue inspected by a trained professional to ensure that the correct repair is made.
when the motor is cold it starts right up, when the motor has been running it won’t start until the motor cools
ANSWER : Hi! Sometimes when electronic components are failing they can be affected by heat. They may work when cool but not when hot. The electronic control module on your Dodge that controls ignition spark is the suspected culprit here. I suggest checking for spark while it’s hot to see if this is causing the no start. If you need help getting this looked at, a certified professional from YourMechanic can come to the location of the car to diagnose the starting problem and have this addressed correctly.
Car A/C won’t stop blowing even with car turned off, can I unplug blower motor resistor ?
ANSWER : Yes, you can disconnect the resistor or the blower motor to stop the power drain. You can do this until you can get it fixed anyway.
Why won’t the starter motor engage and turn engine over. Also, the clutch pedal won’t move and the clutch is partly engaged but slips.
ANSWER : If the clutch pedal is not moving and the clutch is partially applied, then the clutch release bearing may be damaged and the fork is jammed into the clutch forcing it to slip.
For the no start condition on the starter, try tapping on the starter solenoid and see if the starter engages. If the starter does not engage, then remove the starter and see if it engages without the engine. If the starter does engage, then try to crank the engine over by hand and see if it turns. If the engine does not turn, then the bearings may be locked up or there could be an issue inside the engine. If the engine does move, then the starter needs to be replaced. For the brake lights not shutting off, the brake light switch could be applied as it may be not connected properly on the brake pedal. Check to see the location of the brake pedal light switch and adjust the location to relax the switch. If the switch is relaxed, then the brake light switch would need replaced.
I recommend seeking out a professional, such as one from Your Mechanic, to help you with the no start and clutch issue.
Blower motor resistor melted, replaced it turned on blower motor and it melted again in seconds.
ANSWER : The blower motor that is drawing too many amperes will melt the resistor and wiring. Anytime the resistor is melted you should replace the blower along with the resistor and connections that show any heat damage. If you need assistance with this, consider YourMechanic, as one of our mobile technicians can diagnose electrical issue and help you replace the blower motor and resistor as necessary.
Cruise control turns on at idle, but when the car reaches 10 mph the cruise turns off and won’t turn back until idle again.
ANSWER : Hi there. Check all of the grounds to the vehicle and see if there is any wires that are damaged from the taillight short. A loose ground will cause multiple problems with the electrical system and some or multiple components will not work. If you need further assistance with your electrical issues, then seek out a professional, such as one from Your Mechanic, to help you.
Car won’t turn over. No lights come on when I turn it. Can’t even lock my doorsvor push the seat up or back.
ANSWER : Your probably correct, it sounds as though your battery is done. But it also sounds like you have charging system issues. I’m not sure that fixing your battery and charging system will solve the problem with the car shutting off, but it’s possible that it will and it’s a darned good place to start. By contacting Your Mechanic, you can have a technician come to your home or office to check out your car and help you figure out what to do next.
