If your blower motor slows down when accelerating, it may have nothing to do with the motor itself. Many vehicle manufacturers use vacuum motors to operate heating/AC doors. Most vehicles have at least two of these vacuum motors. The fix involves tracking down the bad vacuum motor or the leaking vacuum line.
Why does my car AC slow down when I accelerate?
The reason for this issue is that your air conditioning system is directly tied to your motor —so as you cool off you’re effectively applying some of your horsepower when you set your climate controls to cold air.
What are the signs of a bad blower motor resistor?
Usually a bad or failing blower motor resistor will produce a few symptoms that can alert the driver of a potential issue.
- Blower motor stuck on one speed.
- Blower motor does not work on certain settings.
- No air from the vehicle’s vents.
Can a blower motor get weak?
Weak airflow is a sign of blower motor failure. This part wears out eventually, meaning its fans can no longer push adequate amount of air out the vents or through window defrosters. In other situations, air may not blow out on some speed settings at all. Ask your mechanic to check it out.
What controls the blower motor speed?
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.
What are the symptoms of a bad air compressor?
Some of the signs of a bad A/C compressor are as follows.
- A Lack of Hot Air Being Released Outside.
- Loud or Strange Noises From the Unit.
- Failure of the Compressor to Turn On.
- Circuit Breaker Tripping.
- Leaks Around the Air Conditioning Unit.
- Warm Air Instead of Cool Air Being Delivered to the House.
- Reduced Airflow.
Why should you turn off the AC when racing?
When drag racing you might be asked to turn off your AC (by the track officials) because it drips water on the track. So its pretty common knowledge to turn your AC off when drag racing at a track. In addition, it could also slightly reduce power.
Why does my blower motor work sometimes?
When a blower resistor fails, the highest fan speed usually is the only one that still works because it essentially bypasses the resistor and receives the maximum amount of voltage. When the resistor is working, it reduces the amount of voltage going to the lower fan speeds so the fan runs slower.
How often do blower motors go out?
Even though the manufacturer states their blower motor will last two decades, we advise all clients to expect a 10-20-year life span due to age, use, and proactive maintenance.
What does a bad blower motor sound like?
A defective blower motor will make a continuous sound noticeable by the passengers in the vehicle. It can manifest as a knocking, whirring, clunking, vibrating, squealing, or whining noise that persists until the blower motor is replaced.
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.
How can I make my blower motor faster?
Adjusting the Blower Speed You can increase or decrease the blower speed by slightly adjusting the pulley on the blower drive motor. To increase blower speed, slightly loosen the setscrew that holds the pulley to the driveshaft. Move or turn the pulley clockwise on the shaft one turn, then tighten setscrew.
Blower motor slows down upon acceleration
What kind of automobile is this for? Which is better, the 96 STS or the 95 Eldo? Regardless, do you have a copy of the FSM (Factory Service Manual) for the automobile in question? It becomes increasingly valuable as your vehicle ages and you want to maintain it for an extended period of time. Also, it’s possible that the vacuum motor that moves the air door/valve is in working order. It’s possible that you have a leak somewhere else in your automobile. One test is to start the engine and let it idle for a few seconds before continuing to run it.
Allow it to go, then strike it again, allow it to go, then strike it again.
When you do this, does the engine slow down significantly or do the brakes become difficult to apply?
Depending on whether this is the case, you may notice that the air begins to blast out of the defroster rather of the dash vents.
- After then, switch off the engine.
- Before the brake becomes difficult, you should be able to get two or three good solid pumps out of it.
- This is why having an FSM will be your greatest friend in the long run.
- Considering that my 2003 STS’s temperature control system is powered by bi-directional electric motors rather than by suction, I am unsure about the configuration of your system.
- The vacuum actuators/motors that regulate the Climate Control system are used to operate the system.
- This, I assume, is where the vacuum is stored for the Climate Control System.
- There could also be something in your temperature control system called a ‘Programmer,’ which is in charge of orchestrating the movement of all the doors and other components.
- Once again, get and analyze an FSM.
- I believe you have a vacuum leak somewhere in your system.
- The reason I believe this is because everything works OK during periods of high vacuum (such as when the throttle is mostly closed, for example).
- I’m guessing it’s the Vacuum Tank Assembly or a hose that connects it to the Programmer, now that I think about it.
when you open up the throttle). In addition, a check valve on the vacuum source side of the Vacuum Tank assembly should be included (hose that runs to the intake manifold). It’s possible that the check valve is not working properly (e.g. not closing).
AC fan changes speed while driving.
No1, I had the same same problem and I was able to solve it. It is significantly better now, but it is still no1. I replaced the batteries with two Odyssey 2150 rechargeable batteries (group 31 batteries) 2. I do not have a heating grid (it shouldnt even come on at this temp) Three-quarter-inch-gauge five-kilowatt-strand power cables with beefy terminals are used for all three of the “big three.” This comprises grounding the block and chassis, powering the crossover, getting power from the alternator, and getting power from the starter.
- I changed the blower motor with three different brands of blower motors (vdo, orlieys dont remember the brand, and now OEM) 6.
- Replaced the resistor with a new one (only used on positions 1-3, not on full blast) 8.
- I recently went inside the room with a volt meter and discovered that the current (ground) passes via the selector switch (1-4) and the resistor (only on 1-3).
- From there, I enter a relay that is linked in the manner shown above.
- 87 blower motor ground wire (not cut, but soldered into, it still needs connection for 1-3) Hopefully, this may be of assistance to someone.
A/C blows harder under acceleration.
Re Somewhat similar to that, I was experiencing problems with my own. It was years ago that my foot vent quit functioning, but I only used it about 2-3 days a year, so it wasn’t a major concern. Then my defrost became stuck open, which was driving me insane because my windshield was always fogged in. It would sound similar to what you described, in that it would appear to accelerate up then slow down. So I finally got around to it tonight; the vacuum box is conveniently located near the gas pedal (to answer your question).
- They were fine, and I could see the floor actuator, which had a red hose attached.
- Following that, I removed the middle bezel to have access to the controls (the car is so brittle everything was breaking lol).
- So I realized at this time that the controller had failed.
- It nearly appeared as though the rubber diaphragm had jumped out of its holder and smashed into the floor.
Then I said, what the heck, and took a razor to it, carving out new channels and putting it all back together, and it worked! (with lots of glue). Everything has been restored to normal operation! Sorry for the long narrative, but it may be relevant to your situation as well.
Signs of a Bad Blower Motor
Among the most significant components of your vehicle’s heating and air conditioning systems is the blower motor. In the absence of one, you will be unable to regulate the temperature of your cabin – not a life-threatening situation, but certainly a huge irritation in extreme heat or cold. It goes without saying that your temperature control systems may fail in a variety of ways, so it’s important to know how to recognize the indicators of a malfunctioning blower motor and have it repaired without having to replace a whole bunch of other perfectly excellent parts.
Getting Some Air Time
This little rotary motor is used to operate a fan located behind your vents, forcing hot or cold air through them at changing speeds depending on your choice of fan speed. Despite the fact that it is contained within a housing, it is located in the engine compartment, and it is not uncommon for extraneous items to be pulled into, wrapped around, or stuck in the fan. Because the impeller blades are made of plastic, it is quite simple for them to become detached. When this happens, you may first detect a noise emanating from just behind the vent, such as light slapping or a sharp snap, before realizing that there is an issue with airflow.
Is there a difference or an increase in noise when the fan speed is changed?
Air on the Side of Caution
The blower motor is a tiny rotary motor that operates a fan that sits behind your vents, forcing hot or cold air through them at varied speeds based on your decision. It is possible for foreign items to become sucked into and wrapped around or stuck in the fan despite the fact that it is housed in a housing in the engine compartment. Being made of plastic, it is quite simple for the impeller blades to come loose and fall out of the machine. When this happens, you may first notice a noise emanating from just behind the vent, such as light slapping or a sharp snap, before realizing there is an issue with the airflow.
The fan speed has an effect on the noise level; does it decrease or increase?
Blowing Smoke at You
If you ever see smoke or a burning smell while driving, you should pull over immediately and call for assistance. Although a burnt blower motor or motor wire will not result in the entire loss of your vehicle, you should be certain that this is the source of the smoke before continuing on the road. While it’s conceivable to have a short circuit or a burned-out engine that produces smoke and burning odors, it’s also possible to have something else going on. Check under the hood to be sure it’s not anything else.
Also, with the engine turned off but the key in, check to see whether the smoke and odor rise when the air conditioning is turned up to its highest setting.
Although not a safety hazard in most cases, a malfunctioning blower motor can significantly diminish the comfort of your vehicle during hot or cold weather.
For routine maintenance and repairs, visit one of our 17,000 NAPA AutoCare shops or shop online for all of the electrical system goods available.
Talk to a qualified specialist at your local NAPA AUTO PARTS shop for additional information on the indicators of a failing blower motor. Blair Lampe provided the photographs.
Blair LampeView All
Blair Lampe is a professional mechanic, blogger, theater technician, and wordsmith residing in New York City’s Flatiron District. Backpacking anywhere her boots will take her, rock climbing, experimental theater, a fresh rosé wine, and showering love on her 2001 Sierra truck are some of her favorite pastimes in her spare time.
(’14-’18) – Vent fan (blower) speed changes.
This is a problem that I’m experiencing as well. Do you know of anyone who has experienced the problem and can confirm or refute that Tsb 11-173-17 has resolved it? Did something else come into play and resolve the situation? I have a feeling that because my vehicle is a 2017, Tsb 11-173-17 has already been applied, but I am not certain. Forester XT Touring with Dual Climate Control (2017 model year) When the accelerator is only slightly depressed, the fan speed will fall considerably as a result.
- This is a problem that I’m encountering as well! Do you know of anyone who has had this issue and can confirm or refute that Tsb 11-173-17 has resolved it? Thanks in advance. Did something else come into play and resolve the problem? I have a feeling that because my vehicle is a 2017, Tsb 11-173-17 has already been applied, but I am not certain about this. Touring model with dual climate control for the 2017 Subaru Forester XT When the accelerator is barely depressed, the fan speed will decrease considerably.
AC air volume slows to stop during commute
I’m in possession of a 2008 JKU X. Standard. The air conditioning blasts very chilly air. My issue is that after approximately 15-20 minutes of driving at highway speeds, the air coming from the vents gradually slows down to the point that no air comes out of them. The fan does not slow down its rotational speed. I have to either completely shut down and restart the jeep or turn off the fan entirely for a period of time before the regular air volume is restored. Only for the numbers to begin to drop once more.
In addition, air is not routed to defrost vents or the floor of the vehicle.
It’s a little strange.
One of these was installed into a TJ, however it caused the air flow to be diverted to defrost vents when the vehicle was accelerated aggressively, in addition to gradually diverting over time.
While acceleration does not affect air volume in this situation, it does appear to prolong the time the air conditioner is operating at highway speeds, or more accurately, stable RPMs.
As well as identifying the location of the tank in order to maintain vacuum?
Despite the fact that 2008 is listed in the TJ through present Wranglers in my Chiltons for Wranglers, it is of little assistance.
He’s a bright youngster.
– KarlThis message was sent from my iPhone using Tapatalk.