Air blowing at feet even when the face setting is selected

[invmgmt]

So...maybe I just noticed it, but when I have the fan control switch at the "panel" location, I am noticing air also from the floor vents. When I read the owners manual, it says that there will be some airflow from the window vent (defogger), but no mention of the floor vent. Any ideas? Is this common? Or is there a common (read: not expensive) fix?

2005 LJ

 

[AndyG]

Everything is vacuum controlled-

You can actually remove the glove box and look there and under the consul on the driver side and see the solenoids operate when you turn the switch

If you’re losing vacuum then it’s not holding the doors all the way closed or open whatever the case may be and you’re getting air sent both ways

Start with the under the hood and you’ll see that it’s pulling vacuum off the intake

The first test that I do is to see if the cruise control works

 

[Longwhitejeep]

I have the same issue with my 2005 lj. I'm trying to diagnose it. Did you ever get this fixed?

Mine will blow heat out floor vents but not at the same rate if you select floor vents only. What I mean is switching from floor vent only to center air vents does reduce air flow to the floor but not entirely.

Ac on it will be waem air through floor vents but with a reduced fan speed.

I think my floor vent door is partially closing. Cruise control still works and it holds vacuum from the t connection under the hood.

Any ideas on where I should look next?u research seems to indicate the 05/06 are special with blend door sticking issues.

 

[AndyG]

I have the same issue with my 2005 lj. I'm trying to diagnose it. Did you ever get this fixed?

Mine will blow heat out floor vents but not at the same rate if you select floor vents only. What I mean is switching from floor vent only to center air vents does reduce air flow to the floor but not entirely.

Ac on it will be waem air through floor vents but with a reduced fan speed.

I think my floor vent door is partially closing. Cruise control still works and it holds vacuum from the t connection under the hood.

Any ideas on where I should look next?u research seems to indicate the 05/06 are special with blend door sticking issues.

you have an actuator that is just above the center console under the dash- This will have one of the colored lines that pulls vacuum on it- It is to the driver side of the center console- That controls air movement And you can override it with your hand - If the actuator is not holding vacuum then it needs to be replaced and they are sold at parts stores-

There is another one that is basically behind the glove box and to the right behind the passenger side front speaker-

You can literally crank the vehicle and turn the selector and see these do their job

The blend door is electronic and variable , it is basically wired in above your left shin if you are in the passenger seat- You can put on a stethoscope and hear it operate

I would start with the one that’s just about the console- Don’t be intimidated by this it is a very simple system-

It is also possible to lose vacuum at the switch in the dash- or the line from the switch to the actuator- but the actuator is can stick, become unhooked or leak.

P.S. - I’m not trying to take over the conversation I just have this fresh in my mind and wanted to offer what I could- dont let it intimidate you - there are only 3 zones (defrost, dash and feet) controlled by 2 actuators if I’m correct, all the switch does it distribute the vacuum pull, and the primary blend door is electronic - im sure there is an actuator for the fresh air vent to , but it likely is not causing the zone issue- Andy

 

[Longwhitejeep]

you have an actuator that is just above the center console under the dash- This will have one of the colored lines that pulls vacuum on it- It is to the driver side of the center console- That controls air movement And you can override it with your hand - If the actuator is not holding vacuum then it needs to be replaced and they are sold at parts stores-

There is another one that is basically behind the glove box and to the right behind the passenger side front speaker-

You can literally crank the vehicle and turn the selector and see these do their job

The blend door is electronic and variable , it is basically wired in above your left shin if you are in the passenger seat- You can put on a stethoscope and hear it operate

I would start with the one that’s just about the console- Don’t be intimidated by this it is a very simple system-

It is also possible to lose vacuum at the switch in the dash- or the line from the switch to the actuator- but the actuator is can stick, become unhooked or leak.

P.S. - I’m not trying to take over the conversation I just have this fresh in my mind and wanted to offer what I could- dont let it intimidate you - there are only 3 zones (defrost, dash and feet) controlled by 2 actuators if I’m correct, all the switch does it distribute the vacuum pull, and the primary blend door is electronic - im sure there is an actuator for the fresh air vent to , but it likely is not causing the zone issue- Andy

Thanks for the tip.
I have vacuum at the reservoir and back to the intake connection so under the hood all hoses and connections are goof.

I have it all hooked to a mtiyvac in the engine bay where it enters the cab for now to check to see if any setting/actuator may be leaking. I can move the lower actuator by hand without vacuum to close up the foot well vent but it still allows air through which leads me to believe it may be the door that closes in the dust not sealing or closing all the way. That lower foot vent actuator is holding vacuum and no arms are bent or broken.

All other settings hold vacuum as well. I checked the manifold at the hvac switch/controls and can operate each actuator and hold it with the mityvac.

 

[AndyG]

Thanks for the tip.
I have vacuum at the reservoir and back to the intake connection so under the hood all hoses and connections are goof.

I have it all hooked to a mtiyvac in the engine bay where it enters the cab for now to check to see if any setting/actuator may be leaking. I can move the lower actuator by hand without vacuum to close up the foot well vent but it still allows air through which leads me to believe it may be the door that closes in the dust not sealing or closing all the way. That lower foot vent actuator is holding vacuum and no arms are bent or broken.

All other settings hold vacuum as well. I checked the manifold at the hvac switch/controls and can operate each actuator and hold it with the mityvac.

You’re doing great and I think you’re on the right track

 

[AndyG]

I wonder if a little scope could be ran in there to see what’s going on

 

[AndyG]

You know I’m not trying to be funny but sometimes my only goal with these is for everything to work- all on the same day. TJ’s are just old enough and quirky enough to keep us chasing things- I don’t know how many times I’ve gone to sleep mentally trying to solve some little deal on mine.

 

[Longwhitejeep]

I wonder if a little scope could be ran in there to see what’s going on

I may see if I get one down there. I'll check the heat blend door actuator as well because it's strange the low volume air coming through the floor vents doesn't match the temp set for the rest of the vents. It's always hot.

And I did confirm it is in fact coming from the floor vent not a shift boot or other firewall grommet.

You know I’m not trying to be funny but sometimes my only goal with these is for everything to work- all on the same day. TJ’s are just old enough and quirky enough to keep us chasing things- I don’t know how many times I’ve gone to sleep mentally trying to solve some little deal on mine.

Same. I'll go to bed late tonight thinking about what to check next.
My wife mentioned something about it yesterday saying hot air was coming through the floor vent but ac was on with cold air coming out the center vents.

 

[AndyG]

Did you look at the back of the switch where the colored hoses go in? Heat from the illumination bulb will cause failure- Because you have several things going at once it leads me to think that you’re getting some crossover inside that- You can disconnect those hoses and use the mighty vac there too- I did

You have to be careful getting aftermarket switches- I think it’s the 2006 that has the slightly smaller diameter hose fittings- But please don’t quote me on that.

When I changed mine out I had to keep some parts from the original unit because of that.

Also I can’t remember but some of the components you can buy independently- I just called around the parts stores and got the entire assembly because I was trying to shotgun the problem

You may have a couple of things going on at once- Manually overriding should close that foot vent , So I can see where it’s a head scratcher

 

[freedom_in_4low]

I need to check this out too. I get a little warm air on my feet when I'm driving with AC out the dash. Cruise works though so I at least have some vacuum.

It's tough working on this stuff when it's needed. My garage faces south and gets sun allll day so when it's 98 outside it has to be 110 in there.

 

[Longwhitejeep]

Did you look at the back of the switch where the colored hoses go in? Heat from the illumination bulb will cause failure- Because you have several things going at once it leads me to think that you’re getting some crossover inside that- You can disconnect those hoses and use the mighty vac there too- I did

You have to be careful getting aftermarket switches- I think it’s the 2006 that has the slightly smaller diameter hose fittings- But please don’t quote me on that.

When I changed mine out I had to keep some parts from the original unit because of that.

Also I can’t remember but some of the components you can buy independently- I just called around the parts stores and got the entire assembly because I was trying to shotgun the problem

You may have a couple of things going on at once- Manually overriding should close that foot vent , So I can see where it’s a head scratcher

Yeah I have checked those out too using this diagram I found online. I used a trail fitting on my mityvac to simulate the vacuum circuit for each setting and accumulator. Nothing showing as any vacuum leaks. No arms seem to be broken which I am finding is common on at least older tj's.

 

[Longwhitejeep]

I need to check this out too. I get a little warm air on my feet when I'm driving with AC out the dash. Cruise works though so I at least have some vacuum.

It's tough working on this stuff when it's needed. My garage faces south and gets sun allll day so when it's 98 outside it has to be 110 in there.

Yeah the air isn't very much but on a really hot day it makes a difference. Your feet get. Turning it on center and floor vents does reduce the hear in the foot well vents but not to the same temp as the center or defrost vents.

 

[AndyG]

I can see your concern for the gasket on the door not sealing

I hate when something pops up and you know it’s going to be hard to get to to fix

 

[macleanflood]

On my 97 when I pulled the dash and box to change my heater core...it was amazing how much stuff settled into that box....no cabin air filter...20 some odd years of debris will eventually jam doors or keep them from closing.

Might need to pull the box and clean everything out.

You can inspect your heater core and AC at the same time and lube up all the hinges.

-Mac

 

[Longwhitejeep]

I wouldn't pull the box from the dash until quality heater cores are back in stock for later models tj's.


Performance radiator has been OOS for months now with no expected date.

I will do some more diagnostic this week and see what I can figure out.

 

[Jerry Bransford]

I feel so fortunate I only had one HVAC problem in 26 years of TJ ownership and that was on my previous '97 TJ. A wire cable had come off its actuator connection so it was easy to repair. I think I'd have to live with the problem if something happened to my 2004's HVAC system. Or fly Andy to Florida to help me figure it out lol.

 

[rouxbicon]

Interestingly, my '03 has "leaked" a little airflow through the floor vents when only the dash vents are selected, pretty much since new. The controls work as they should, but apparently the mode door that directs airflow doesn't seal off the floor vents completely when dash vents are selected.

In my case however, it is cold air if a/c is on. I never dug into it with any enthusiasm. When my wife complained that her feet froze when she wore sandals or flip-flops and the a/c was running, I started plugging the floor vents with a piece of foam rubber through the summer. Pretty ghetto-fab, but it works...

 

[Sancho]

you have an actuator that is just above the center console under the dash- This will have one of the colored lines that pulls vacuum on it- It is to the driver side of the center console- That controls air movement And you can override it with your hand - If the actuator is not holding vacuum then it needs to be replaced and they are sold at parts stores-

There is another one that is basically behind the glove box and to the right behind the passenger side front speaker-

You can literally crank the vehicle and turn the selector and see these do their job

The blend door is electronic and variable , it is basically wired in above your left shin if you are in the passenger seat- You can put on a stethoscope and hear it operate

I would start with the one that’s just about the console- Don’t be intimidated by this it is a very simple system-

It is also possible to lose vacuum at the switch in the dash- or the line from the switch to the actuator- but the actuator is can stick, become unhooked or leak.

P.S. - I’m not trying to take over the conversation I just have this fresh in my mind and wanted to offer what I could- dont let it intimidate you - there are only 3 zones (defrost, dash and feet) controlled by 2 actuators if I’m correct, all the switch does it distribute the vacuum pull, and the primary blend door is electronic - im sure there is an actuator for the fresh air vent to , but it likely is not causing the zone issue- Andy

Did you replace the main heater/blend door actuator hinge? The hinge that pivots the door.

If so... where did you get it? Dealership was not helpful.

 

[Longwhitejeep]

Interestingly, my '03 has "leaked" a little airflow through the floor vents when only the dash vents are selected, pretty much since new. The controls work as they should, but apparently the mode door that directs airflow doesn't seal off the floor vents completely when dash vents are selected.

In my case however, it is cold air if a/c is on. I never dug into it with any enthusiasm. When my wife complained that her feet froze when she wore sandals or flip-flops and the a/c was running, I started plugging the floor vents with a piece of foam rubber through the summer. Pretty ghetto-fab, but it works...

I have thought about this too for the summer. It's not a high volume of air that leaks past and my system seems to be passing all the vacuum checks.