Air won't come out of vents? Read this!

Chris

Chris

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It seems this issue comes up from time-to-time, and it's very common among TJ owners. This happens even on my TJ from time to time. I'll get in the car, start it up, then go to turn the air to blow on my face (instead of my feet) or some other position, and air won't come out anywhere but my feet or the defrost setting.

There's a few reasons this can happen.

Your blend door is stuck
If that is the case, see this post here:
https://wranglertjforum.com/threads/air-wont-come-out-of-vents.2034/#post-23747

You have a vacuum leak
If that is the case, see this post here:
https://wranglertjforum.com/threads/air-wont-come-out-of-vents.2034/#post-103618


Those are the two most common causes for this issue.

If anyone has any input, tips, or suggestions on this subject, please feel free to share them. Just thought we needed a thread about this since it is fairly common on TJs.
 
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I’m getting air from every vent but the two in middle of dash. When I turn control to the head or feet setting on heat fan doesn’t run on either. Runs on any other settings. 01 Tj with air
 
I'm getting air thru my vents. But sometimes it's intermittent. Like I'll start up the car with the air set to AC/dash vents (settings from the last time I used it). And nothing comes out for maybe 30 seconds. Once it does the air is sufficient. But not really a hard blow. Could I have some debris in my vents? How hard to they normally blow? The heater seems to blow hot enough air. To have to turn it down after a short while. But I'm in Socal. So It's not like getting it warm fast in freezing weather. I guess what I'm saying is the air blows hard enough to heat the car. And the ac cools the car. Just not super fast. I do have a soft top with cloth upper doors.

AT this point it's not enough to make we worry. But once I move to a more extreme climate. Just wondering if this is a sign that my heater blower is going out or the switch or something? And that maybe my vents need cleaning out?
 
Any advice for air not blowing thru the center vents? My selector changes the airflow from the floor vents to the dash vent and to the defrost, but when the dash vents are selected, only the outside vents blow air. Would a vacuum leak cause only the center vents to not blow air?

Thanks

PD
 
P_D said:
Any advice for air not blowing thru the center vents? My selector changes the airflow from the floor vents to the dash vent and to the defrost, but when the dash vents are selected, only the outside vents blow air. Would a vacuum leak cause only the center vents to not blow air?

Thanks

PD
Click to expand...

Yes, it's almost always either a vacuum leak or a broken blend door actuator.
 
Thanks, Chris! I had the whole dash off (replacing airbags) this past winter- maybe I damaged an actuator in the process. But I’ll check the vacuum lines too.
 
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P_D said:
Thanks, Chris! I had the whole dash off (replacing airbags) this past winter- maybe I damaged an actuator in the process. But I’ll check the vacuum lines too.
Click to expand...

Let us know what (if anything) you find!
 
New here but this thread topic stood out. I had the issue blowing only dash and floor, found the vacuum line along the firewall (engine side) was cut. I was in the process of moving and didn't have time to order the line. Took a hollow electric wire crimping tube and electrical tape and reconnected the line. Two years later still working.
 
My issue with a lack of airflow through the dash vents continues, but it seems intermittent. Sometimes air blows, sometimes it just squeals and whistles.

I don‘t have any test equipment, but I poked around under the hood a bit. I didn’t see any obvious cuts or crimps in the vacuum line. I wiggled the connections and they all seem secure, so I removed the kickplate under the dash to get a good look at the actuators.

I started the Jeep and moved the selector and I can see that all the actuators move when selected, except that sometimes the dash actuator doesn’t always respond to the selector knob. I can reach in and give it a little nudge and that seems to wake it up. It will move and air blows through the dash as advertised.

Does this sound like a partial vacuum situation? (that may not even be possible...I have never messed with vacuum systems before, so I’m uneducated)

Or does this sound like a bad actuator?

I sure appreciate the advice...
 
P_D said:
My issue with a lack of airflow through the dash vents continues, but it seems intermittent. Sometimes air blows, sometimes it just squeals and whistles.

I don‘t have any test equipment, but I poked around under the hood a bit. I didn’t see any obvious cuts or crimps in the vacuum line. I wiggled the connections and they all seem secure, so I removed the kickplate under the dash to get a good look at the actuators.

I started the Jeep and moved the selector and I can see that all the actuators move when selected, except that sometimes the dash actuator doesn’t always respond to the selector knob. I can reach in and give it a little nudge and that seems to wake it up. It will move and air blows through the dash as advertised.

Does this sound like a partial vacuum situation? (that may not even be possible...I have never messed with vacuum systems before, so I’m uneducated)

Or does this sound like a bad actuator?

I sure appreciate the advice...
Click to expand...

It sounds like it could be either. You need to rule out vacuum leaks first, which is going to require a smoke machine, no two ways about it. Your eyes aren't going to be enough to spot some of the places a vacuum leak can develop.

I would rule that out first before going any further, honestly.

There are a number of YouTube videos as well that detail how to make your own smoke machine.
 
If I hadn’t already been familiar with your posts and your history of sound advice, I would be certain that you are pulling my leg.

"Youre going to need a laser light projector and the vinyl version of Pink Floyd’s The Wall..."

I’ll check out YouTube and check back in when I have something to report.

Thanks again!
 
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P_D said:
If I hadn’t already been familiar with your posts and your history of sound advice, I would be certain that you are pulling my leg.

"Youre going to need a laser light projector and the vinyl version of Pink Floyd’s The Wall..."

I’ll check out YouTube and check back in when I have something to report.

Thanks again!
Click to expand...

Haha, no problem at all, I know what you mean.

The smoke machine thing sounds silly, but it really works.

The last guy who had this issue found his vacuum leak underneath the battery tray on the passenger side if I remember correctly. It was somewhere you'd have never thought to look.

Vacuum leaks can be very, very tricky to track down with the naked eye, which is why I suggest ruling it out first. The HVAC system is vacuum controlled, so it's the first thing to check.
 
Okay I have all the necessary parts to cobble together a smoke machine. Most of the YouTube videos are for other makes and models, or for evaporator leaks. So I am improvising here.

Here is my plan:

1.) unplug the vacuum line right here:



1587347278491.jpeg

2.) attach the smoke machine to the line and apply a little pressure

3.) look for smoke escaping along these lines and fittings:

F9F7A17B-6679-4777-B4EC-518669165150.gif

Smoke escaping anywhere in the line or the fittings or the reservoir or the check valve means I have a leak, so I should shop for a new vacuum harness.

No smoke means no leak, so I should shop for a new actuator.

Am I on the right track?
 
Sancho-
I’m no expert, but if there is air blowing through the floor or the dash or the defrost, the blower motor is working. If the airflow doesn’t change from one to the other at all when you move the switch, then maybe it’s the switch. If the airflow moves from one to the other, but won’t work on one of the selections, then its probably the actuator or a vacuum leak. That’s what I’m reading from all the experienced guys that post on the forum.
 
Mine was a vacuum leak
 
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