2001 Cherokee Sport.

I've been aware of this problem for about a week. Regardless of the dial setting - the fan only blows out the defroster outlets. Any thoughts appreciated.

 

No sure on your year of Cherokee but a vacuum leak can cause this on older vehicles. The dampers use engine vacuum to open and close. The defrost is typically the default setting if there is no vacuum (from a leaky line example).

 

https://picasaweb.google.com/ken384/...eat=directlink

Open this link and review each photo of the vacuum system in your engine compartment. Typically, there's a rubber connector rotted or off, or the plastic tube is chaffed or broken.

To view the vacuum reservoir connection, lay under the right front bumper end cap and pull the plastic wheel well liner down and look forward at the reservoir connection.

There have been findings of the tube behind the battery broken.

Is your cruise control inop? If so, it would be a broken line in the system.

 

Thank you both.

This is by far the best vehicle we have ever owned (in 60+ years) and she has been very pampered. I've got to tell you though - I'm feeling a little worn down by these problems that are cropping up caused by aging hoses etc. We would love to drive this Jeep for 10 more years. Has anyone ever seen a guide to 'restore' all the rubber/plastic engine components so we can just bite the bullet once ? Does that even make sense ?

Merry Christmas !

 

I'd start at the vacuum ball. It's located on the passenger side, behind the front bumper. Work back from there.
Mine acted the same way & it was a hose off of the ball.

 

We had to replace the radiator within the past month. Perhaps something came loose. Thanks.

 

Had the Jeep into the shop again today - new high pressure power steering hose and a new front engine gasket - ($170 USD which I think is a bargain since they had to lift the engine out to replace the gasket). I printed off all the pictures of possible vacuum leak points. They went over the system again and came to the same conclusion they had come to a month ago - the problem is inside the dash. For years, when the air was on high little bits of grey foam would spit out at you from the vents. I wonder if a larger chunk of foam is stuck someplace it doesn't belong ? The mechanic thinks there is a little door in the dash which is stuck/broken. He says it is a lot of work to remove the dash.

Any thoughts appreciated. Happy New Year !

 

You probably have had your blend door hinge inside the dash break. I have the same problem with my 97 and only get heat out of the defrost setting. Lately I have learned to live with it and just wear thicker socks and gloves and hat in the vehicle when I go out for a ride. No problem as there is plenty of hot air coming from the defrosts vents. There is a way to fix it through the glove box. There are a few YouTube videos about how to fix the blend door broken hinge problem. If you are a handy guy you could probably fix it yourself.

Don't pay an arm and a leg to have someone rip your dash apart trying to fix this. It CAN be done thru the glove box. Remove dash you're talking BIG bucks to do. Also look up on the net something called Heater Treater. That will give you schematics of what I am talking about and a fixit video for that product.

 

Thanks for the suggestion. btw - My wife was born and raised in Columbus.

 

Just down the road about 120 miles from me.......I'm in Wooster in Wayne County - you know right around the corner really. Hope you get your baby looked at. I'm not going to bother with fixing the blend door thing on mine....It's just me and my son so basically this is a two seater XJ for us with both rear seats folded down for cargo room and he's usually complaining I have it too warm in the cab to suit him. Now no heat complaints out of Sir *****aLot LOL

 

Thanks for posting this link.. this is excellent info.

 

The little door the shop mechanic was referring to is the Defrost Door, not the Blend-Air Door. The Blend-Air Door has nothing to do with your problem. Bits of foam clogging the front side of the AC Evaporator would cause low aiorflow through the system, not stuck in defrost mode.

The crank arm connected to the defrost door could be broken off, with the door left in the open position. To get at it for a look you would have to remove the upper dash and a few other items.

To see if the Mode Selector on the Climate Control Panel is getting vacuum from the engine, you can roll down the glove box and look straight in and somewhat down. There you can see the inlet of the MAX AC (recirculation) Door (with the door open you can see the blower fan).

Start the engine and look at the recirc door. See if the door opens and closes when you move the Mode Selector from MAX AC (the first detent out of off (O) to any other selection on the Mode Selector. If the door opens and closes you are getting vacuum to the Mode Selector, but this is not assurance that you are getting vacuum to the Defrost Door Actuator. You'll have to remove the upper portion of the dash to see the actuator and the Defrost Door. You do not have to remove the HVAC Unit to see the door/actuator.

 

CCKen,

could i get you to repost that google document link? i have a leak, vents stuck on defrost, but also going to replace heater core and ac evap. want to kind of look over everything since it'll be a deep dive.

 

This is a very old thread - but I just received an email of a new post.

We resolved this problem perhaps 6-12 months back. I'm sure I posted the resolution here - perhaps on another thread. Our mechanic pulled the dash and found that the 'box' that holds the flapper which directs the air direction was cracked in a way that the flapper could not flap. Had absolutely nothing to do with vacuum leak, They repaired the box. Been working just fine since.

Also - I had been afraid of what might happen if they pulled the dash - but in the end that was a non-issue.

 

I put a new vacume ball on I have now air coming out of vents and floor again but the air is cool any idea now how to get warm air?