Rexx66

Only have air blowing out of the defrost vent on top of dash. Getting heat but nothing out of vents.

I keep looking for something that I think it should look like but I've never seen a picture of it, or even where to look in the cab or under the hood.

I just picked up a 90 Wagoneer Limited and trying to fix this, and a few other minor problems.

Also is it possible the cruise control is related to the vent issue I'm having. Researching on Google and saw someone on a forum say they are. Please help I'm new to XJs and come from the world of CJs

jeepfreak82

If cruise doesn't work, then first place is to look for a vacuum leak. The old soup cans they used for vacuum reservoirs were bad to rust out where they are hard to see. Would check all vacuum lines for dry rot or cracks and be sure that is right first. Your vents will not change without vacuum as that is how the actuators work. Also, if you notice nothing under the hood, listen inside for any hissing sounds while it is running as the tubes to some of the controls for the blend doors are plastic and may break, though this is a less common problem.

STUD IN THE MUD

I have this same issue. Interested to see if you figure it out.

Rexx66

Ok so after a few hours of learning the vacuum system on this thing I found the problem. There is a small vac line that goes into the firewall right next to a power wire which is located right next to the coolant lines going to the heater core. I had a melted hose which was easy enough to fix, ziptied the vac line away from the coolant hoses which I'm assuming is what melted it.

Started up and sweet baby Jesus the vents are a blowin... Woot woot hope anyone else having the problem is similar in ease. The line runs along the inner fender on passenger side and goes to the firewall area close to the the coolant lines.

Bobolink

Even if the cruise control DOES work, you have a vacuum leak in the black plastic vacuum tube that controls the heater/AC controls. The cruise control and HVAC controls are separated at the vacuum reservoir. The reservoir has two separate chambers on trucks with cruise. You will need to look really hard, and also inspect by TOUCH to find the small hole in your line. I would start 4-5" from where the line enters the firewall, underneath the coolant pressure bottle (if you have a Renix era model, or a similar area near the heater hoses in a newer model). This is where the chafing usually occurs. Any rough spots you can feel in the plastic line will almost certainly be a hole. Cut the line there and splice with an appropriately sized piece of vacuum hose.


EDIT.....didn't notice that you had found it....good for you! Glad it's fixed.....yours is a very common problem.

STUD IN THE MUD

Im going to give this a shot, i have a feeling mine is the exact same problem

CCKen

Open this link.

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

There's pics of the vacuum system, including the broken HVAC source tube and a fix for it.

STUD IN THE MUD

Wow this is very helpful! thanks man!

STUD IN THE MUD

This was super helpful. The hose behind the battery was cracked in half. I fixed it up with some 7/8ths vacuum tubing and my A/C works perfectly now. Thanks for the info!

CCKen

Glad to help STUD, and glad you got it fixed.

BTW - 7/8" tubing? Really? LOL

STUD IN THE MUD

Yes, well rubber hose rather. I simply cut off the brittle cracked portion of the original line and slid the new rubber hose over each end to join the two together. Lol its been a few days and still working great. I was gunna order the OE replacement but hey it works. Thanks again!

almido

Had this problem on an xj a few years ago. It was a POS and I owned it less than two weeks. Traded it back to dealer....


Got a 2001 two weeks ago, couldn't be happier. Had the no heat/no cruise problem. Fixed it today.


It seems the black plastic vacuum line that runs out from the firewall, along the pass side fender (usually under the cruise vacuum motor) and down to behind the bumper has shrunk. I'm thinking maybe a chemical problem that makes it act like shrink tube a little over time.


Anyway, it shrunk shorter by three inches and pulled itself off the nipple on the vacuum ball. Cut it, slipped on a 4 inch piece of vac tube and "Bazinga", back to normal operation.

cruiser54

Exactly why I advocate relocating the vacuum bottle to the engine bay. Here's one on an 87: