air only comes out of my defrost

It sounds as though the recirculation door inside your dash has broken or disconnected and is no longer allowing movement of air to the proper ducts when selecting. I suggest taking this to a dealer simply because there is a great deal of disassembly to get to this point, as well as dealer-only part involved.

get used to it. It seems to happen a ton on jeeps. Don't take to a dealer...they'll rip you a new one on labor for something like this

Check the vacuum lines to the door controls. These lines are routed directly to the engine manifold and the door fails to the defrost position on loss of vacuum. Maybe a line has come loose or a leak has developed in the line.

there is a motor that controls the door its located on the driver side just above the floor vent this piece is 45 dollars at auto zone I suggest u take the silver rod off and move the white control up if that don't work then u may professional help

Anybody who happens to float to this post one thing i did was check the vacuum line attached to manifold if that is fine then one more thing to check would be to follow the vacuum line and check for any holes or rips if nothing continue on and take out the headlight on the passenger side and behind where it sits should be the vacuum reservoir that is where i found my broken vacuum line one mechanic suggested to me that it could be the blend doors IT IS NOT THE BLEND DOORS FOR THIS SPECIFIC PROBLEM. Do not go wasting money getting the blend doors fixed if it could just be a vacuum line

Agreed kingsnapple, check the vacuum lines first. Start by checking under the hood on the firewall, next to the heatercore/blower motor area. You'll find a hose with a "T" on it. First, follow the one line that goes towards the battery. Check for holes rips and tears. Next, check the other line on the "T" fitting, It will run up and over the engine to the drivers side near the Intake manifold. Chances are the vacuum line just popped off. Check that before taking to the "Stealership"

I discovered wiggling the tiny vacuum line that goes in through firewall above the heater core pipe caused the heat to go from defrost to floor (dial control turned to floor heat). I'll double check vacuum lines for leaks before I dismantle dash.

I've dismantled my entire before to fix a speaker wire that was pinched. It took an hour or more to dismantle yet I found it easy.

Today I located black vacuum line from heater control dial to where it exited firewall by pulling it back and forth. In the photo I included, I broke the thin plastic vacuum line at point A by accident. The thin plastic line broke off inside rubber line B. I then disconnected the line from the main rigid plastic line and found I could not blow through it. Where the small line broke off in rubber line B I trimmed it off and then could easily blow through it. I slid the thicker rubber line B over the thin plastic line coming out of firewall. I then turned heater control dial to floor and heat transferred from the defrost vents to floor vents. Problem fixed.

Same problem on my 2000 Cherokee classic. Took it to the dealership, was told to expensive to fix :). Didn't believe the vacuum line story above. But did go out and checked it. Found the problem! The vacuum line was broke at the battery! Thanks guys.

Good to hear SamuelJ

Lumbeegal87 is the only person I have found ON THE INTERNET to mention this part. Which is the ONLY thing that has made my HVAC change the locations it is blowing out of. Thanks for not repeating the same thing everyone else is saying.

had the same issue.after reading your post I checked my vacum lines and found a cracked one at the t connector by the cruise control.fixed that and it works better but still not 100 percent.I'm thinking we are on the right path.Thank you for all you help.

I don't know much at all about cars but while my husband was under his jeep grand Cherokee with the hood up I was on the drivers side looking at I guess the motor, I saw a small pipe just hanging there and I also saw a place it looked like the pipe was suppose to go in so I put it in and it fixed the problem....

Thanks caribou 4x4. You were right about the little plastic hose. The picture helped alot. I couldn’t have found it without it. Fixed the problem in less than 5 minuets

Thanks guys had the same problem... hose was disconnected at the engine... that was way too easy!

We just fixed this problem in 5 minutes. Cracked hose by firewall passengers side. Cut inch long cracked piece off & shoved further in. Works perfect now! Thanks everyone!

i have the same prob. it is intermitent. no vacume leaks anywhere. there is a check valve near the manifold. i replaced with one from pick and pull. 95 on a 2004. works better but not right. On exceloration the dash switches back to defrost. i cant find the name for this part so i can get the right one for my jeep. anybody know?????

Stumbled across this thread and had been having same issue with air(hot or cold) stuck in the defrost mode regardless of dial location. Vacuum line under battery tray on canister had a crack right at the connection. Fixed with no further issues. (don't removed the whole bumper, just the passenger side headlight assembly)

When I start my 2007 Grand Cherokee, I sometimes hear a clicking noise I think is from the air diverter servo motor. Where is this part located, and how hard is it to get to?

Checked vacuum first. My break was off T fitting on passenger side fire wall. Cleaned rubber T out of old broken piece and shoved line back in same place. Fixed in five minutes. Have a 1992 XJ

does anyone have a picture of what the hose looked like that they reconnected? im having the same problem in my 2004 jeep grand cherokee with the fan stuck on defrost and when i looked today i saw a thicker pipe not connected to anything under the hood dripping liquid so im assuming its part of the AC? i know nothing about cars but everything that people are saying seems to be whats happening with mine. also when its on defrost the two outside vents on the driver side and passenger side do faintly blow so im not sure what to do. thanks for the help!

Hello Caseymae, this is Chad Parks. The hose to be on the lookout for will be a black rubber hose, that is approximately 1/4" to 3/8" in diameter. If you have the inline 6 cylinder engine (4.0 Liter), this small hose will be hooked onto the intake manifold, which will be the silverish steel assembly bolted onto the upper right side (drivers side) of the engine. The large plastic tube coming off the air cleaner housing will be routed over to and mounted on the intake manifold. You'll need to look down and around the intake manifold and you'll see some small rubber hoses that are connected to the manifold. These hoses simply slide onto small ports on the manifold. This is where you'll likely find one of the tubes has either simply become disconnected and pulled off its mount, or may have became brittle and dry-rotted and could possibly be cracked right where it mounts onto the manifold or is partially disintegrated and allowing only partial vacuum. The tube that you've mentioned in your post is just a small drain line. which allows the moisture that was collected from inside the vehicle to drain to the outside of the vehicle and is not associated with the air flow issue. Let me know how it turns out. Chad

What about on a V8 have defrost but nothing else. Where do the vacuum lines go

GuruLSQYF. This was our problem easy fix the 1/4 black hose was cracked and fell off where it connects on manifold! The guy at dealership service department didn’t believe me I told him to put new hose on it and connect it and it will fix it cuz it happened twice. It fixed it!!!! Now I have air to all my vents not just defrost vent!!!!!! I love you tube saves me a ton of money especially when dealership says that is not the reason!!!

Hellow Mama50CLUB, please I have the same issue but I don't understand how to do it . Could you tell me how by steps. Thanks

Same problem. Air from the defrost only. A little electrical tape on the split line and a zip tie to keep it off the hose. Works fine again.

Then whats this

Vacuum leak was my problem. The defroster is the default position if there is a vacuum leak

Yes, you have a vacuum hose that has came dislodged on the engine intake area. Look at all the small black tubes around the intake manifold and see if one has worked its way off its mount, or the rubber may be dry rotted or cracked where it mounts to the manifold.

Vacuum hose going to drivers side

I recently replaced the purge control value and same issue with blowing through defrost vent. Could this be the problem?

Yes, I'd check all the vacuum hoses under the hood just to ensure they're still intact where they mount onto their connection points. (they could have small cracks which won't let the hoses pull the correct vacuum to the diaphragms that operate the blend doors within your dash) I have the inline 6 cylinder and the vacuum hose on my intake was about a 1/4" in diameter and mounted directly to the intake manifold.

Thanks

I just bought a 2003 Jeep Grand Cherokee Laredo 4.7l V8, when I test drove it with the owners the air conditioner was working fine blowing thru the vents, we went back to where we met paid for it and left, i couldn't get the air to come out of the vents, so when we got home I messaged her and asked her if there was a trick to it and she said the hose popped off again, I looked and couldn't find nothing can someone please help me?

Hey Sheri....look at the plastic duct where the air is directed into the engine. That duct will be mounted to what's called the "intake manifold". On that manifold,(usually made from iron or aluminum nowadays) there should be rubber or plastic hoses(of various sizes) that are slid onto connection ports. These connection ports are mounted on the intake manifold, because of the vacuum that's needed to operate various things, of which, yours is likely one of the HVAC blend doors within the dash. Look around very carefully at the hoses that go to that manifold and ensure each of them are connected thoroughly an slid entirely up onto their mount port. The size of the hose should be somewhere between a 1/4" up to maybe a 3/8" hose. If you find a port that looks to be missing it's connection hose, simply look around that immediate area and locate the hose that's either vibrated off, or has been pulled off somehow. Also, be advised to look at each of those connection points to see if there's any "cracks" on the rubber or plastic hose that may have developed right where the hose mounts to one of the ports on the manifold. If there is a crack, you may not be getting full vacuum needed on that hose, which connects to the diaphragm under the dash to operate the blend doors to direct airflow from the various air outlets(floor vents, dash vents, defrost vents). Best Regards and Best of Luck, Chad Parks

I have a 95 Jeep Cherokee NOT GRAND. I’ve been having an issue with the doors closing under engine load (only driving). I replaced all lines from the vacuum chamber to the cruise control. I also replaced the t joint that goes into the fire wall. Not sure if this is would be a problem under the dash or have something in the engine bay still leaking. Been scratching my head about this for a while and could use some input! I live in AZ too.

The way to fix this problem, if your main vacuum lines are connected, there is a small vacuum line right behind the passenger side headlight that connects to the resovoir, I looked into it for weeks then saw this, pulled the headlight off and it was disconnected, it's about a 5 inch hose, finding this prob saved me a few hundred by not taking it in, fixed it for nothing!!

air blowing through defrost only? on my 2001 jeep Cherokee i found a small black plastic broken line coming from the firewall near the heater hose. i put a coffee stir/straw on the lines and brought them together/now i have air coming from the vents.

Just fixed mine! Was the tube behind the passenger light. Crack fixed with electric tape