I have a 2014 Chevy Suburban and the A/C works fine when I start driving. I would say after about 30-45 of driving the air slowly stops blowing out of the vents. If I turn the A/C on high, I can hear the fan going full speed but no air is coming out the vents. I just hear the loud blowing sound behind the glove compartment. The rear A/C works fine. I've done some internet searching but can't come up with anything. Thought about the cabin air filter being plugged but wondered why it works and then stops. Then when I start driving again, it will blow out the vents again. Didn't know of a connection from the blower to the vents disconnected but as I said before, after not driving for a while, it will blow out of the vents again.

Any thoughts? Thank you!

BBGigem said:

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I have a 2014 Chevy Suburban and the A/C works fine when I start driving. I would say after about 30-45 of driving the air slowly stops blowing out of the vents. If I turn the A/C on high, I can hear the fan going full speed but no air is coming out the vents. I just hear the loud blowing sound behind the glove compartment. The rear A/C works fine. I've done some internet searching but can't come up with anything. Thought about the cabin air filter being plugged but wondered why it works and then stops. Then when I start driving again, it will blow out the vents again. Didn't know of a connection from the blower to the vents disconnected but as I said before, after not driving for a while, it will blow out of the vents again.

Any thoughts? Thank you!

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There's a resistor that controls AC flow under the glove compartment. Have you ever changed it out? Most of my AC issues in modern GM vehicles have been caused by it.

No I haven't changed it out. Have had suburbans for years and this is the first time I've had this happen. Of course, it may have been done and I don't remember when I had it serviced. It is fairly easy to do myself?

Frozen expansion valve/evaporator?

Now that sounds way over my head. Was hoping this would be something fairly easy to do. May end up needing to take it to the shop. At least the temps are starting to go down. But this is Texas and we always seem to need our A/C.

Swapping out the blower motor resistor is pretty easy. Pretty sure there are youtube videos that walk you through it. I had an '08 that had similar symptoms and it fixed it. I replaced it at least two times. Also went ahead and replaced the wiring that ran from that to the blower motor. Ordered the parts off of Amazon.

BBGigem said:

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No I haven't changed it out. Have had suburbans for years and this is the first time I've had this happen. Of course, it may have been done and I don't remember when I had it serviced. It is fairly easy to do myself?

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Yep, it is simple. You just have to be able to tolerate being on your knees for a bit, while kneeling outside the truck on the passenger side. I wear knee pads when I do it, but you could use a pillow or cushion. The work itself, takes about 15 -30 minutes, depending on how much stuff you have to remove in your specific model, and if your replacement part is OEM. (OEM has the right wiring harness and connectors) Otherwise, you will likely need to cut off the plug, and remake the connections. I have done both in various vehicles. It is a very easy cheap replacement, so I usually try it first with all AC issues that have similar symptoms.

It's not the blower, not the resistor, not high blower relay. The evaporator coil is frozen up and no blower is going to blow through a block of ice. Likely has low charge. Put gauges on and check charge and pressures after it's in the frozen state.

Also this vehicle is likely part of the series that had extended warranty period due to condenser leaks. I believe all the extensions have expired but still likely to leak eventually if condenser has not been changed

If the blower is still making noise, can you feel air coming from anywhere else? Like the defrost or floor?

1agswitchin4lanes said:

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If the blower is still making noise, can you feel air coming from anywhere else? Like the defrost or floor?

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No. Not coming out of any vents of any kind. Well, I can tell when it is starting because the speed of the air out of the vents starts fading until it gets to nothing. Sometimes when I fool with the recycled air switch and go back and forth with it, it will "fix" itself. But usually that is just for a short time.

I'm not sure if I am just more sensitive to this because there is a problem but I feel like there is more water under the vehicle after it has stopped for a while than before. But then again, that could just me looking for things since there is an issue.

Drove from San Antonio to Round Rock and back yesterday. It did it thing oh about Kyle. Then it starting working again for about 10-15 minutes then stopped going through the vents again. But on the way home, and I took a detour so the trip was longer, it worked fine the whole time.

Thanks for all of the ideas!

When it does this, I suggest you pull over and go to the passenger footwell and feel the blower motor and see if you can feel the motor spinning.

If it is still spinning, my guess is that you have a mode door actuator that's stopped or failed.

If it has stopped spinning, my next guess is that you have a blower motor that has a bad connection of some sort, either a bad solder joint on the and motor connectors or an issue with the brushes etc thats causing the motor to stop spinning.

-or-

Typically if the blower motor resistor is bad, the AC fan will still work on high. Sometimes this isnt the case with the new Auto Climate controls. If the resistor is bad, then it just sh\ts the bed and you're done.

Fortunately, the Blower Motor resistor is around $30 bucks and the blower motor is about $35-55 bucks.

If you're feeling lucky, maybe pick up both on Amazon and try replacing each and return the one that didn't fix it.

Basic hand tools and about an hour of your time will set you straight.

If you're more apt to do diagnosis, you can pull out a DVOM and start looking at voltage at the connector that plugs into the blower and do diagnosis, but seeing is that you're looking at less than 100 bucks to replace both items, (possibly only one), it may not be worth the time. I typically dont like 'throwing parts' at repairs but in this case the risk is low and accessibility isnt too bad.

They still call it a resistor but its not a "Resistor" its a module that controls the voltage to the blower motor but not the typical 3 wire wound resistors on piece of phenolic. Same function but can't determine failure by looking for burned wire or ohm meter. The normal failure mode is the connector melts due to heat and many include replacement harness you can splice into your existing wiring.