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Resistor

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How to Replace a Cooling Fan Resistor
The cooling fan may not work at all speeds if the resistor is broken. If the engine overheats or the fan never turns off, the resistor may be faulty.
Symptoms of a Bad or Failing Ballast Resistor
Common signs are the vehicle not starting or starting but immediately dying. Only a professional mechanic should handle the ballast resistor.
How to Buy a Good Quality Heater Blower Motor Resistor
Vehicles Vehicles that are equipped with a manual HVAC, or climate control, system utilize a blower motor resistor to control the speed of the heater blower. If you are driving a minivan or an SUV with a separate rear passenger...
Symptoms of a Bad or Failing Cooling Fan Resistor
Common signs include the engine overheating, cooling fan only working at certain speeds, and the fan never turning off.
How Long Does a Ballast Resistor Last?
A A ballast resistor is a component in the ignition system of older vehicles. If you drive a classic, you are familiar with coils and points. You don’t have an onboard computer, and obviously you don’t have circuit boards that...

Related questions

Door lock problems
Hi there. There is a resistor for the door locks that keep a voltage on the driver door lock cylinder to activate the secondary door locks electronically. If the resistor is leaking (losing power) it tends to cause the door...
Air not flowing out of front vents.
If the blower motor is not turning, the cause is identified during a failed heater diagnostic (https://www.yourmechanic.com/services/heater-is-not-working-inspection). Blower motors failures are due to faults in the wiring, fuse, relay (https://www.yourmechanic.com/services/blower-motor-relay-replacement), control switch (https://www.yourmechanic.com/services/blower-motor-switch-replacement), resistor block (https://www.yourmechanic.com/services/heater-blower-motor-resistor-replacement), if so equipped, and...
2014 Ford Focus Blower Resistor Location
If you have Electronic Manual Temperature Control (EMTC), the blower motor resistor block is accessed by removing the accelerator pedal. Once the pedal is removed you will see the wiring harness to the block and the single retaining screw that...
After hour or so driving, engine starts to sputter as if not receiving fuel. Stop for 10 mins and it runs fine.
The stalling could be due to a heat induced failure of the ignition coil. Resistance of electrical components increases with temperature and if the coil is the issue that is why the stalling only occurs once the engine is hot....
Why does my blower motor not work after a crossed wire problem in my 2004 Pontiac Grand Prix
Hello. Depending on exactly where the short was it may not blow the fuse. Most of the time it will melt the resistor itself internally. It may also have a short in another location. I usually take a voltage meter...
The heat, ac, and defrost isn't blowing out the vents
Blower speed in your application is controlled by a replaceable resistor block in the blower motor circuit. If various fan speeds have become unusable, and now you are left with nothing, a possibility is all positions in this resistor block...
Why does my front blower motor not work on my 2013 Toyota Highlander
Hello. If the blower motor is not working it is typically caused by an issue with the resistor, though it can be the motor itself. I usually check to see if the motor is getting power. If it is getting...
Burnt yellow and brown wires at blower motor resistor, is this indicator of bad resistor or bad motor? 2011 Chevrolet Malibu
Hi there - most likely, the problem is the blower motor resistor pack (https://www.yourmechanic.com/question/heater-does-not-work-by-todd-d). A quick way to test this is if the blower fan still works in the "Max" position. If it does, that pretty-much rules out the motor...
HVAC Blower Motor Fan runs on high Speed all the time
This may be related to a faulty blower motor control module or resistor. The blower motor resistor (https://www.yourmechanic.com/services/heater-blower-motor-resistor-replacement) controls the various speeds and functions of the blower motor once it is turned on. I would recommend having an expert from...
Is a transistor and a blower motor resistor the same thing?
When you were told to replace the resistor or the transistor the person that told you did not know if you had manual or automatic a/c. Your car will have a blower resistor for manual a/c blower controls and a...
Blower motor not working
If your heater only blows when the setting is on high, this may suggest that you have a faulty blower motor resistor (https://www.yourmechanic.com/services/heater-blower-motor-resistor-replacement). The highest speed setting may still work because in most cars in the highest fan speed settings...
My car ac a year ago stopped working on settings 123 only works on 4 I did the research so I do know it is the blower motor an ha
In your application, there is a replaceable blower motor resistor block. The resistor block permits multi-speed operation of the fan. If some fan speed settings work, but not others, the first thing to do is test the resistor block with...
My fan for my a c and heater is only blowing air on 2 3 and 4 settings but not 1
The blower motor resistor, in the motor speed control circuit, is probably faulty. If your vehicle does not have automatic temperature control, the part that needs to be replaced is relatively inexpensive. If you desire a definitive diagnosis, and replacement...
Defroster works - hot or cold air depending on what temperature you have it on, but not vent or heat. 2011 Ford Edge
Hello - your symptoms suggest that the HVAC blower motor resistor (https://www.yourmechanic.com/article/how-to-buy-a-good-quality-heater-blower-motor-resistor) has failed. The blower motor resistor limits fan motor speed for the Low and Medium settings, but is not involved at the Max setting. Since defrost on most...
2007 galant es blower motor resistor or transistor
Your vehicle is equipped with a blower motor resistor block. It is a modular, replaceable assembly and the part is different for Galants with and without A/C systems. If your blower motor is not functioning, failure of the resistor block...
How do I know if it's my blower motor resistor or the resistor switch that's not working?
The referenced parts are tested with an ohmmeter. The resistor block (https://www.yourmechanic.com/services/heater-blower-motor-resistor-replacement) must have a specified resistance across each element on the block. However, if any resistors are open (infinite resistance), the block is just condemned and replaced automatically. Occasionally,...
Heater only works on high
It sounds like you may have a faulty blower motor potentially drawing too much power from the resistor causing it to burn itself up. As you know, the individual blower motor resistor (https://www.yourmechanic.com/services/heater-blower-motor-resistor-replacement) inside the pack are usually wire wound...
Blower Fan Run Very Slow At All Speed Selections
The speed of the fan blowing is generally controlled by the resistor which you have already replaced. Occasionally, the blower motor itself can fail also causing this type of problem, however it sounds like you have replaced this also. The...
Blower motor resistor and transistor.
Your car is not equipped with a transistor for the blower motor. Your car has a blower resistor that controls the speed of the blower motor with the changes to the blower switch. The burning smell you are getting may...
My blower motor is not working on 2008 Hyundai Sante Fe
Hello, thanks for writing in. The blower motor resistor is what controls the different modes (i.e. high speed, low speed, etc.) of the motor. The blower motor relay is what controls the power to the motor in general. I would...

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