Your GMC Acadia AC keeps blowing hot air, and you’ve tried to fix the system. But nothing seems to work.
Does this sound like you? Then you are at the right place.
In this post, I’ll show you how to diagnose the problems in your GMC Acadia AC. You’ll also learn how to troubleshoot each issue. First, let’s look at the possible causes of this problem.
Reasons Your GMC Acadia AC is Blowing Hot Air
Low Refrigerant Level
A low refrigerant level is the most common reason the GMC Acadia AC won’t cool.
Before your AC can blow cool air, all the heat in the system has to be removed first. The refrigerant gas makes this possible by absorbing and releasing the heat from the indoor air into the condenser.
If you don’t recharge your AC frequently, your refrigerant levels will fall. Since you don’t have enough refrigerant gas, some of the heat in your AC will remain in the system. This excess heat is eventually released from the AC vents as hot air.
If you haven’t recharged your AC in over a year, chances are your refrigerant levels are low. As such, you’ll need to refill your AC with more freon.
If you fill your AC with too much refrigerant, the AC might blow hot air.
Your refrigerant needs to switch between liquid and gaseous states to absorb and release air easily. But when the refrigerant in the AC is too much, it might be unable to change into a gaseous form. This causes the heat to stay in the AC.
Usually, your AC becomes overcharged because you recharged the system at a higher pressure value than necessary. The correct pressure value for a GMC Acadia AC recharge ranges between 35-55 psi, depending on the ambient temperature.
If you charge your GMC Acadia AC at a higher pressure value than 55 psi, your AC will be overcharged. In that case, you’ll need to release some of the refrigerants into a rag.
If you aren’t an expert, you may find it challenging to measure the pressure value of your AC recharge. This is why we recommend hiring an expert to recharge your AC.
Another issue that can cause your GMC Acadia AC to blow hot air is a faulty compressor.
Your compressor clutch is the component that pumps the refrigerant gas through the AC, as the gas collects and releases heat. As time passes, your compressor will become faulty and eventually stop working.
Without a functional compressor, your AC cannot remove heat from its indoor air. This leaves the system with no other choice but to blow hot air.
You can tell that you have a faulty compressor if your AC doesn’t start working immediately after you’ve turned it on. Growling noises from your AC might also indicate that your compressor has gone bad.
If you notice these signs, you might need to replace your compressor. You’ll find the compressor in your GMC Acadia underneath the passenger side of your car.
Bad AC Pressure Switch
If your AC isn’t blowing cold air, your AC pressure switch might be faulty.
Before your compressor can turn on, it needs to ensure that your refrigerant pressure is low. Your compressor gets this information from the AC pressure switch.
When a pressure switch gets faulty, it may measure the refrigerant pressure wrongly and deliver incorrect information to the compressor. As a result, your compressor won’t turn on.
Since your compressor is inactive, your AC won’t extract heat from its indoor air. This might be why the AC is blowing hot air.
You can check whether your AC pressure switch is bad by testing your climate control system with an OBDII scanner. If the scanner returns these values: P0530 or P0533, your pressure switch is faulty.
Consider replacing your AC pressure switch if you suspect that the device is faulty. You’ll find the AC pressure switch at the end of the low-pressure port.
A Weak Evaporator Temperature Sensor
Your AC pressure switch isn’t the only component that can prevent your compressor from turning on. If your evaporator temperature sensor detects a poor temperature in the evaporator, your compressor will stay off.
Even when your evaporator is operating under proper temperature, a weak evaporator temperature sensor may report an issue in the evaporator. This will prevent your AC from cooling its indoor air.
The only way to fix a bad evaporator temperature sensor is to replace it. Locate your evaporator temperature sensor behind the glove box in your GMC Acadia.
A Bad Expansion Valve
If your AC is blowing hot air, your expansion valve might be faulty.
The refrigerant in your GMC Acadia AC needs to maintain a low pressure before entering the evaporator coil. Otherwise, it might be unable to absorb the heat in your AC. Your expansion valve prevents the refrigerant from gaining extra pressure.
If you’ve been driving your car for several years, your expansion valve will weaken. As such, your refrigerant won’t absorb the heat in your AC. This causes the AC to blow hot air.
Replace your expansion valve to fix this problem. Search for your expansion valve inside your AC liquid line, which is located between the evaporator and condenser.
A dirty evaporator can also make your AC blow hot air.
The role of the evaporator is to collect heat from the AC and transfer it into the refrigerant liquid. But sometimes, dirt may seep into the evaporator and block its gaps.
A clogged evaporator can’t collect heat or send it into the refrigerant. This means that the heat in the AC will remain in the system. So, your AC will end up releasing hot air from its vents.
One unique sign of a clogged evaporator is a strange odor from the AC. This odor emanates because of the refrigerant liquid stuck in the evaporator.
If your evaporator is clogged, you’ll need to clean it. The evaporator in a GMC Acadia is located behind the dashboard.
Your AC might fail to blow cold air because your condenser has gone bad.
Your condenser is responsible for releasing the heat in your AC into the air outside your system.
Like other components in your AC, the condenser can develop issues. When this happens, it will lose the ability to do its job. This will force the heat to remain in the AC. Eventually, the hot air will circulate through your AC and move into your car through your vents.
You can tell that your condenser is bad if the AC emits a burning odor. Change your condenser if you smell this odor from your AC. Your condenser is located behind the front bumper of your GMC Acadia AC.
Broken Cabin Filter
One of the common reasons why your GMC Acadia AC might blow hot air is a bad cabin filter.
The cabin filter extracts dirt from the ambient air before it reaches other parts of the AC. After a while, the dirt in the filter sinks into its deep layers.
When this happens, dirt in the ambient air may escape the filter and move into other AC components, thus clogging them. As a result, these components won’t be able to remove heat from the AC. This forces the system to blow hot air.
You can tell that you have a bad cabin filter if only a little air comes out of your vents. To fix this issue, you’ll need to replace your cabin filter. Search for your cabin filter underneath your glove box.
Bad Blend Door Actuator
Another culprit that causes the GMC Acadia AC to blow hot air is a bad blend door actuator.
Your blend door actuator ensures that the AC releases air at your preferred temperature. It does this by blending air from the heater core and your cooling system until your desired temperature is achieved.
As time passes, the blend doors in the actuator may weaken and get stuck. If your blend doors stop working while your cooling system is closed, your AC will only blow hot air.
If you keep hearing tapping noises when you turn on your AC, you can be fairly certain that your blend door actuator is faulty. In dual-zone GMC Acadia models, a bad blend actuator makes the AC blow hot on one side and cold on the other side.
If you discover these issues in your AC, it’s time to replace your blend door actuator.
Most GMC Acadia models have two blend door actuators: the driver’s side and passenger’s side blend door actuators. You’ll find the driver’s side blend door actuator behind the kick panel on the driver’s side. However, the passenger’s side blend door actuator is at the back of the glove box.
Blown AC Fuse
Sometimes, your AC might blow cold air even when all the components in the system are working properly. In such cases, the malfunction in the system might be a result of a blown fuse.
To fix this issue, you’ll need to inspect all the fuses related to the AC in your car. If any of them looks blown, replace them.
Broken Climate Control Unit
Although quite uncommon, a broken climate control unit can cause your AC to blow hot air. Whenever you add a new setting to your climate control system, the system delivers the settings to the AC.
Over time, the buttons on the climate control unit will loosen and eventually stop working. If you were using your heater before the climate control unit stopped working, your AC would only blow hot air until you’ve replaced the unit.
How to Fix ‘GMC Acadia AC Blowing Hot Air’ Issues
Recharge Your AC
An AC recharge is one of the most common ways to troubleshoot a GMC Acadia AC when it blows hot air.
You’ll need an R134a refrigerant can, an AC recharge kit, protective gloves, and glasses.
Follow these steps to recharge your GMC Acadia AC:
- Wear your protective gloves and glasses
- Open your hood. Then get your R134a refrigerant.
- Start your car and switch on your AC.
- Turn the switch to Full Cold. Then set the Fan to Max.
- Look for the low-pressure port on the engine bay. This port is usually labeled with an L.
- Remove the cap on the port. Then connect your AC recharge kit to the port.
- Shake your refrigerant can for a few seconds.
- Connect the can to the recharge kit to release the refrigerant into the port. Then shake the can again and pour the refrigerant through it.
- Keep shaking the refrigerant can until you attain your desired pressure value.
You can check the pressure value on your recharge kit.
Replace Your Compressor
If your AC is blowing hot air, you can fix it by replacing the compressor.
Here’s how to replace the compressor in a GMC Acadia AC:
- Make sure you’ve already recovered the refrigerant in your AC.
- Walk to the engine bay.
- Locate your low-pressure hose near the engine firewall.
- This hose is the large line connected to the compressor.
- Remove the 10-mm bolts linking the hose to the compressor.
- Detach the front wheel on the passenger side of your car.
- Go under your vehicle.
- You’ll notice a metal flap covering the compressor.
- Remove the pushpins on the flap to reveal your compressor.
- The next step is to detach your tensioner belt from the compressor.
- Take a picture of the belt before you remove it.
- This will help you remember how the belt was positioned on the compressor.
- Loosen the left tensioner arm linked to the compressor.
- Unscrew all the bolts on your compressor with a 13 mm socket. Then remove your old compressor and insert the new one.
- Re-attach the bolts on the compressor.
- Reconnect your front wheel to your car.
- Screw your low-pressure hose back onto your compressor.
Change Your AC Pressure Switch
If your GMC Acadia is blowing hot air, you can try replacing your AC pressure switch to see if that will fix the issue.
Take the following steps to replace the AC pressure switch in your GMC Acadia:
- Disconnect the plug on your low-pressure or high-pressure AC port.
- Use a 16-mm socket to remove the pressure switch.
- Insert the new pressure switch and replace the plug you removed earlier.
Replace your Evaporator Temperature Sensor
You can also prevent your AC from blowing hot air by replacing the evaporator temperature sensor.
Use these tips to replace your evaporator temperature sensor:
- Disconnect the negative terminal on your battery.
- Lower your glove box.
- Remove the screws on the lowered glove box with a 7 mm socket and wrench.
- Remove the plastic panel at the bottom of the passenger-side dashboard.
- You’ll need a 7 mm socket to remove the screws on the panel.
- Next, unscrew the T10 bolts linking the upper glove bin to the dashboard.
- Tug the glove bin carefully to pull it out.
- You’ll see the evaporator temperature sensor in the opening behind the glove bin.
- Use the tip of a screwdriver to disconnect the electrical harness on the sensor.
- Now, you can access the sensor.
- Use a long-nose plier to cut off the area of the dashboard that houses the sensor.
- Insert a clothes hanger into the hole you’ve created to pull out the sensor.
- Get your new sensor and insert it into the dashboard.
Change Your Expansion Valve
An old expansion valve can cause your GMC Acadia AC to blow hot air. This is why you should consider removing your expansion valve to fix the issue.
The guide below will help you remove and replace the expansion valve in your GMC Acadia:
- Pull out the AC liquid line from the firewall on your engine bay.
- Remove the screws on the expansion valve.
- Detach the old valve and connect the new one to your car.
Clean Your Evaporator
Cleaning your evaporator is another way to troubleshoot your AC when it is blowing hot air.
The evaporator in a GMC Acadia AC is located behind the dashboard. So, you’ll have to remove your entire dashboard to access it.
If you aren’t an expert, you may damage an electrical connection in your vehicle while trying to remove your evaporator. This is why we recommend hiring a professional to clean your evaporator instead of doing it yourself.
Replace Your Condenser
You might consider replacing your condenser if your AC is blowing hot air.
The guide below will show you how to replace the condenser in your GMC Acadia:
- First, hire an auto technician to recover the refrigerant in your vehicle.
- Turn off your engine and wait for it to cool down.
- Remove all the bolts on your front bumper with a T20 socket. Then pull out the support panel at the top of the bumper.
- Find the AC discharge line and disconnect it from your condenser.
- The discharge line is located between the condenser and the compressor.
- Also, search for the AC liquid line between the condenser and the expansion valve.
- Remove the liquid line from the compressor.
- Remove the flaps on each side of the radiator.
- Press the tabs at the top of the condenser.
- Now, slide out your condenser carefully.
Replace Your Cabin Filter
Replacing the cabin filter in a GMC Acadia AC is another effective way to fix cooling problems in the AC. This is because the cabin filter can allow debris to block and damage main AC components like the compressor, the evaporator, and the condenser.
Here’s how to replace the cabin filter in a GMC Acadia AC:
- Open your passenger-side glove box.
- Detach the glove box from the dashboard.
- You’ll see the cabin filter now.
- Press the tabs on the cabin filter to release it from the dashboard.
- Slide out the filter and replace it with a new one.
Replace Your Blend Door Actuator
Is your GMC Acadia AC blowing hot air on one side and cold air on the other side? Then, the blend door actuator on the side that’s blowing hot air is faulty.
Since the faulty blend door actuator can be on the driver’s or passenger’s side, you should know how to replace both.
We’ll show you how to replace your driver and passenger-side blend door actuator below.
Follow these steps to replace the blend door actuator on the driver’s side of your GMC Acadia:
- Search for your kick panel under the driver’s side dashboard.
- Remove the pushpins on the kick panel with a trim tool.
- Slide out the panel.
- You’ll discover a plug linking the panel to the dashboard.
- Turn the connector to loosen it from the kick panel.
- This will reveal your heater box.
- Search for the blend door actuator inside the heater box.
- You’ll find a connector on the blend door actuator.
- Press the tab on this connector to disconnect it from the actuator.
- Remove the T20 bolts on the actuator.
- Finally, slide out the old actuator and insert the new one.
Use this guide to replace the passenger’s side blend door actuator in your GMC Acadia:
- Open your glove compartment.
- Remove the bolts connecting the glove box to the dashboard.
- Detach your glove box.
- This will reveal the blend door actuator.
- Remove the safety clip on the actuator’s harness. Then release the wiring connector from the actuator.
- Remove all the mounting screws on the blend door actuator.
- Detach the old actuator from the dashboard.
- Place the new blend door actuator and fix back the mounting screws onto the device.
- Re-attach your blend door actuator to the dashboard
Your GMC Acadia AC may not be cooling because you have a weak compressor, a faulty condenser, a dirty evaporator, or a bad blend door actuator. Other reasons why your GMC Acadia AC may start blowing hot air include low refrigerant levels in the AC and weak pressure switches.
One of the fixes above should resolve the issue with your GMC Acadia AC. If you’ve tried all the tips above, yet your AC keeps blowing hot air, contact your dealer.