Drivers of Chevy trucks commonly have issues with their air conditioning systems. These problems are usually attributed to the blower motor. Chevy truck blower motor problems can be very annoying, especially on long roads.
You might face some of these issues. If so, this will help you. First, let’s understand what the blower motor is and how it functions. Then, you will know the common problems and how to fix these problems.
What is the blower motor?
The blower motor is a prominent part of the air conditioning system of any vehicle. This part is responsible for blowing the air, either hot or cold, through the truck’s vents. It has a resistor that controls the blower motor.
Other parts of this system are the blower control module, the AC control head, and the wire connectors. Problems that occur within this system can be related to any of its parts. When one or more of the parts stops functioning, the whole system is affected. Consequently, it doesn’t operate as usual.
Also, you need to know that, as with any vehicle parts, the blower motor with all its parts has an expectancy lifetime. Thus, you have to know this expected time and change them accordingly to avoid future problems.
Chevy Truck Blower Motor’s Common Problems
There are common problems with the blower motor that many drivers notice with their vehicles. They are:
The blower does not work
When you start your truck engine, and the blower motor doesn’t work, don’t immediately think you have to replace it. Even if you switched off the truck and tried again with no response from the blower motor, still there might be another cause of the problem.
Intermittent blower motor operation means the A/C blower works in some instances and stops working in others. When it repeats doing so, this is a sign of a problem. You may start your truck’s engine and switch the fans on, but it doesn’t work.
Out of nowhere, if the fan is still switched on, it will start blowing air. The intermittent blow-no blow is a problem that needs figuring out its roots.
Blower motor stuck on one speed
Sometimes the problem is the blower motor will get stuck at one point even if you change speeds. It means that the blower motor is not responding to the speed adjustments. The problem here is the resistor, but you still need to check other parts of the blower control system.
Weak airflow from the vents
Here, the airflow is less than the one you usually had when operating at the same particular speed. To get the difference between both problems, switch the speeds of the fan.
If the fan works on all settings but blows less air than usual, it is a weak airflow problem. This problem is usually attributed to the end of the lifetime of the blower motor.
No air coming out from the vents
When the AC is turned on, the fan is adjusted to a certain speed, but no air is coming out. This problem means that the blower motor can get power to blow air through the vents. Different parts of the blower motor might be responsible for this problem.
Not working on some settings
Other blower motor problems might include not working in certain settings. It is when the fan does not function in certain settings but works on others.
You may also experience only cold air coming out but no heat even when adjusted on heat settings. A possible cause of this problem is rheostat dysfunction.
Other causes are the resistor or the AC control head itself. Generally, blower motor problems are the same in terms of possible reasons and solutions.
The blower motor may stop responding to the adjustments and then suddenly stop working at all. When it works again, it will work intermittently. Thus, whatever the problem you face with your truck, you need to check all the possible reasons to apply the best solution.
Possible reasons and solutions
Whereas different problems occur for various reasons, it might be hard to figure out the reason behind a specific issue. However, there are some indications. They are listed below.
The blower motor
Your motor might have caused the problem. To check your motor, you need first to make sure that the motor has power to it. Ironically, this might be the problem.
Check the fuses of the motor, and they are all seated in the fuses box. Sometimes, the fuses may loosen and cut the motor’s power, causing intermittent or no operation at all.
Blower motor resistor
Many blower problems are related to the resistor. The resistor is a small electrical part responsible for controlling the fan speed. When you change the fan speed using the knob, the resistor responds and changes its settings to the adjusted speed.
The resistor is the most part that continually fails as it is used frequently. To make sure it is a resistor problem, not the motor itself, turn on the fan speed to the maximum level. If this works, it is probably a resistor problem. Here, it would help if you replaced the resistor.
The resistor harness or plug
Sometimes the resistor harness which connects the resistor to the motor causes the problem. The wiring harness can rust or melt.
This happens when it frequently gets hot, then it melts or corrodes. Also, the plastic plug can melt as a result of excessive heat. In this case, the problem is not within the resistor itself. It is just the harness or the plug that needs replacement.
Some trucks have a rheostat for fan speed control. These rheostats can worn out or accumulate dirt at some points. So, when you adjust your fan speed control to one of these spots, this may cause intermittent operation.
To clean the rheostat, you can do one of these options. First, you can clean it manually by rapidly moving the fan control speed from the minimum level to the maximum.
It may help remove the dirt, but you need to repeat the process more than one time. Also, make sure your truck is off. If the first option didn’t work, you could then try this one.
Get an electric contact cleaner spray and take the HVAC controller out. Spray inside the rheostat to clean the dirt. Then, you may try the first step again to ensure all the remaining dirt is blown away.
HVAC control problems
Trucks with manual HVAC controllers more often have a software issue that stops the blower motor from working. To determine if this is a problem with the HVAC control, you can try this solution.
Turn off the blower motor and the Defrost mode, then switch your truck off. Turn on the truck; the blower motor shouldn’t work as it is turned off.
Now, try switching the mode of the blower motor to another mode either than the defrost mode. If it works, it is mostly a software problem. You can then go to a truck repairer to reprogram the HVAC software to solve this issue.
Blower control module
Some Chevy models have automatic temperature control. This is a digital type that works the same as the HVAC controller. If you have this type in your truck, you need to check if any parts need replacement.
How to diagnose the problem?
Take off the panel on the passenger side to access the blower motor and the resistor. According to your truck model, you may need to swing out the glove box or pull out the bolts. This allows for a good view of your blower motor.
First, you have to check the fuses. As mentioned before, Chevy blower motor problems can be a very simple fuse wiggling out of its place.
Also, the fuses may be worn out, so you need to replace them. Next, check the blower motor itself and the resistor to identify which is not working well.
We recommend you start with the resistor as it is more common that the resistor causes problems. An ohmmeter is the only tool needed to check power reaching the resistor and the blower motor.
Starting with the resistor, it is held by two bolts. You can take it out by dissembling the bolts. Pull it down and remove the power cable. Place one of the leads on the ground and the next to 4 points A, B, C, and D. Check the resistance between these points. If there is continuity in the numbers you get on your Ohmmeter, then the resistor is working well.
Moving to the blower motor, take off the blower motor’s cover, disconnect the power connector; connect the power cable to the resistor again, and then turn on your truck. You can switch the fan speed to the highest level; you should see 12 to 15 volts; then your blower motor is in good condition.
Now, check the blower control module. This is the intermediate connection between the blower motor and the AC head. If the blower motor is working well, as you have just checked, but the AC is not working, it is probably a problem with this intermediate part.
However, the AC head itself can be the problem. The three-wire connector that connects the AC head to the blower control module needs checking. If no power is going through this three-wire module connecter, the problem is within the AC control head itself.
The repairing costs are determined according to the problem. Significant issues will need replacing the whole blower motor; it will cost you something between $40 and $50.
The price may vary according to the model and the seller. If your problem was the resistor, its replacement would cost you around $30 and above. The new resistor kit comes with a harness and plug.
On the other side, the HVAC resistor for manual AC controls is cheaper. It can start at $25. You may need to replace the AC blower control module. It is also around $25.
1. Should I replace the resistor if the blower motor is not working?
Although the resistor is most commonly the cause of the problem, you shouldn’t replace it first. Most Chevy truck drivers do this once their blower motor stops working or dysfunctions. However, you need to go through all the diagnosis steps above, as the problem might be something else.
2. Can I fix the problem or do I need a mechanic?
If you can identify the problem yourself, then you can repair it yourself too. Dismantling the blower motor and its parts is not a hard job. You can follow the steps or watch a tutorial to do it in the right way. Just make sure you correctly figured out the part that needs replacement.
3. What if I replaced the motor or the resistor, but I still have problems?
Probably, you replaced the wrong part, or there is another problem that you couldn’t identify. So, it would help if you went to a professional mechanic to help you find out what caused your blower motor problem.
4. What if there is a water leak under the blower?
The water leak is another problem aside from the common Chevy truck blower motor problems. Before you fix your blower motor, you need to find and fix this water leak problem.
If you have an excellent blower motor with all new parts, a water leak may lead to rust in the resistor. So, you will have other problems along with the main problem.
Although the blower motor’s replacement parts are not very pricy, you shouldn’t go ahead buying them at the first encounter of the problem. Chevy truck blower motor problems have different roots. So, good diagnoses will help you get the right part to replace. Also, you may not need to replace anything, and check fuses and connections are good.