New to Forums... air not coming through vents

[MattyMatt716]

So here's the issue... any help would be GREATLY appreciated. I'm sure the dealership would love to help, but I don't have a money tree (if you do, however, let me know).

Just got the AC fixed- coil was bad. The day I picked it up, everything worked great. About 30 minutes down the road, the air in the vents stopped blowing (blower was still working). I turned the AC off, and this made no difference. The blower (behind the glove box) was working very efficiently- I took the cabin filter out and air was blowing out of the filter hole. Put the filter back in, and no difference.

I turned my car off and let it set for about 5 minutes (coincidental, not because I was troubleshooting). Restarted, and it began working again. About another 30 minute down the road, it did the same thing.

When the AC is on, the air that DOES come through is cold. I don't think it could be plugged- I change the cabin filter more often than I probably need to. The blowing is very intermittent. I can always hear the blower blowing, but the air isn't coming through.

It is almost like I have the vents closed while the blower runs full blast, but everything is wide open (that I know of).

Blend door actuator for a 2006? Any other ideas???

 

[Gunner]

try this..

Check for trouble codes:
The HVAC control unit has a self-diagnostic function for heating, ventilation, and air conditioning system. To run the self-diagnostic function, do the following:

1. Turn the ignittion switch OFF.

2. Press and hold the recirculation control and rear window defogger buttons, and turn the ignition switch ON (II).

3. Recirculation indicator turns on for 2 seconds, then self-diagnostic function begins.

NOTE:
•The blower motor will run at any speed during the self-test regardless of the dial positioning.
•In the case of multiple problems, the recirculation indicator will blink the lowest number DTC only.
•If no DTCs are found, the indicator will not blink.

DTC (Recirculation Indicator Blinks) Detection Item
1 An open in the air mix control motor circuit
2 A short in the air mix control motor circuit
3 A problem in the air mix control linkage, door, or motor
4 An open or short in the mode control motor circuit
5 A problem in the mode control linkage, doors, or motor
6 A problem in the blower motor circuit
7 HVAC control unit internal error
8 An open in the evaporator temperature sensor circuit
9 A short in the evaporator temperature sensor circuit

 

[MattyMatt716]

Thanks for the tip Gunner. I will try this and definitely get back with you. I also notice that the air stays very cold after I turn the AC off.... I wonder if it's freezing or frosting due to the temperature coming out?? Is that even possible?

Either way, I'll go through the self-diagnostic check and let you know.

 

[MattyMatt716]

OK... First, how long does the diagnostic take? I let it sit for a minute or so. No blinking lights.

 

[MattyMatt716]

OK let me be more specific. When I press the two buttons and turn the ignition with to the second position, my blower stops blowing (expected probably). The AC and front defrost LEDs come on. After a short pause (3-5 seconds) the defrost goes off and the AC and front vent LEDs are on along with the recirculation LED. After another few seconds the recirc and AC LEDs go off and the front vent and rear defrost stay on. It appears to do nothing after that.

After I have done this (have gone through the process about 10 times now) the vents begin working again. Sometimes, though, they don't.

Any ideas? Am I not doing something correctly?

 

[Gunner]

Sorry it took me so long to get back to you, let me go try it myself and get back to you.. i got the instructions from the users manual my friend has in his 06..i lost mine..

 

[Gunner]

No if you are doing it as listed above it works...however if it does not blink then it did not detect a problem..if you ran the test when your system was working it wont show any codes you have to try and do it when you are having the problem..

make sure all your vents are open...the fact the blower comes on but no air is coming out is strange but check all your grounds too, make sure all the connections got put back on right and tight since you just had it repaired.

 

[Xouki]

hey matt. i just got an 06 civic lx. and mine is doing the same. i was wondering if you ever got yours fixed. yeah its doing the EXACT same. crazy

 

[lethal6]

His profile page shows that he hasn't had any activity on this site for almost 2 years now. Not likely to receive an answer from him...

 

[MattyMatt716]

Xouki-

Yep, it has been about 2 years. And I'm still having the same problem. I have gone through 2 A/C compressors, and one complete system with no luck. I have gone through 2 heater control units as well.

Honda dealership (Fort Wayne, IN) only wanted to throw parts at it and did not fix it. They wanted to charge me over $500 to change the heater control unit saying that this would fix it (didn't fix it). Took it to another, independent, local company that specializes in automotive A/C systems. No fix yet.

I did my own research and worked with the second company. Bottom line: the A/C compressor will not turn off. Even if the A/C is "shut off" in the cabin (i.e.- no light on the A/C mode), the compressor runs continuously. Having said that, there are days when it works as normal. Other days it does not work properly. The only fix is unplugging the compressor completely.

The second company took a few days to look through the wiring but found nothing. I don't see how it could be anything other than a ground short somewhere. I did replace the relay and this did nothing. I replaced all components but nothing fixed the issue.

If you figure out the answer, please let me know- I am still dealing with it. The lines still freeze up, and the A/C compressor still runs continuously without cycling off.

Any responses to this thread to go my email; if you find anything out, please let me know!! I've gone through two "professionals" with no answers. (Apparently, the Honda dealership called a senior mechanic at the big boys shop but received no answers).

 

[RamRam]

I am also having the exact same problem and would LOVE a solution to this.

I recently had my AC compressor clutch replaced. When I picked up the car the AC worked great, it was a short drive home so I didn't notice the problem. But the next day when I drove it for an hour I noticed that after about 20-30 mins of driving the car, air, cold or otherwise, stopped coming through the vents. I can hear the blower blowing the air, but nothing really comes through the vents. The fan in the glove box is working fine, i checked that, also i recently replaced my cabin air filter so I know it's not that either.

When I picked up the car from the shop they informed me that they got the AC to start working, but that the compressor clutch would NOT disengage so the compressor would continuously be running. They said that there is likely a short somewhere along the control unit and that the cost of replacing that part will be over 250 bucks.

I'm just really confused as to why air will blow fine through the vents then all of a sudden no air comes through the vents at all even though I can hear the blower blowing at full-blast. Any help or insight would be appreciated!

 

[RonJ]

I am also having the exact same problem and would LOVE a solution to this.

I recently had my AC compressor clutch replaced. When I picked up the car the AC worked great, it was a short drive home so I didn't notice the problem. But the next day when I drove it for an hour I noticed that after about 20-30 mins of driving the car, air, cold or otherwise, stopped coming through the vents. I can hear the blower blowing the air, but nothing really comes through the vents. The fan in the glove box is working fine, i checked that, also i recently replaced my cabin air filter so I know it's not that either.

When I picked up the car from the shop they informed me that they got the AC to start working, but that the compressor clutch would NOT disengage so the compressor would continuously be running. They said that there is likely a short somewhere along the control unit and that the cost of replacing that part will be over 250 bucks.

I'm just really confused as to why air will blow fine through the vents then all of a sudden no air comes through the vents at all even though I can hear the blower blowing at full-blast. Any help or insight would be appreciated!

This thread is cluttered, so you'll do better by creating your own thread in a technical forum. Also include information about your car.

 

[MattyMatt716]

I disagree about the thread being "cluttered". We are all still having the same issue, and no one has yet found an answer.

I do think that it is a ground somewhere, but I took it to another mechanic who was not able to find anything wrong. That being said, the problem has tapered off, so I am convinced it is a short somewhere.

RamRam, if you know how to change out your stereo, then you will find that changing out the heater control unit is even easier. The Honda dealership told me it would take approximately 4 hours to replace. I did it myself in 30 minutes. If you shop online, you can find a MUCH better price for the control unit. I think I was priced at somewhere around $200 for the part, and then another $300 or more to put it in. I found the HCU for $120 (shipping included) and did it myself.

BUT.... it did not fix the problem.

I also read somewhere that the problem could be the computer. And I haven't found one of those for cheaper than $400. If I knew that this was the problem, then I would have no problems dropping the $$ to fix it, but I don't want to throw any more parts at my car (not that there are more left to try replacing). The mechanic said that he traced all the wires, but I did not find evidence of this when I looked at the car afterward. I feel like I'm running out of options!

I, too, would absolutely love an answer to this.

 

[MattyMatt716]

Also, regarding the vents not blowing air.... Your blower is working fine. The problem is that the compressor does not cycle and causes a huge amount of frost that ultimately restricts the airflow. To test it- when you stop blowing air through your vents, pull over, pop your hood, and marvel at the amount of frost on your AC line- there will be no question as to which line to look at! It will be the WHITE one.