maximan1

Like the title says, the vents do not work. My A/C blows cold and my heater blows hot, but it only blows from the defrost vents. Now, I have read a few things on here about how it's an under-dash vent line that's broken, and I have found one, but I do not know what it's for or where it goes. Mine looks like it has been cleanly cut off, it's routed under the panel where my hood release is (inside the Jeep), and goes through the same hole the hood release cable goes through.

I would like to get my vents working, because the defrost vents are just not cutting it. My Haynes manual is completely and utterly useless, if there are any vacuum lines going there, they are not listed in the book's diagram. There are actually a couple lines that the previous owner must have run, because I can't find them on the diagrams.

If someone could explain where and how this vacuum line that operates the vents goes, that would be much appreciated. Or even better, show a picture of where and how it goes.

Thanks, Max

maximan1

Forgot to mention, 4.0L I6, 5 speed.

hbracing13

The vent that you are looking for is on the passanger side right? Or is it one the sits right under the center vent. If I rememeber correctly when I took apart my parts jeep there are three or four vac lines that come from the heater core area and are routed to the passanger side, the heater control center, and two vac valves that sit next to your ecm.

hbracing13

Its on the lower right is a pod and the left center lower is another pod and one goin to the control panel

sandfish88

My 1994 jeeps vacuum line broke just behind the engine up against the top of the firewall, I had to replace it with sprinkler drip line, because Im super cheap, but as soon as I plugged it back on the intake manifold and the connector thats just above the windshield washer tank, the jeep started blowing cold air from ALL the vents instead of the defroster vents. Its a default that happens when you lose vacuum.

look for leaks from the end of the line(vaccum bottle located behind front bumper) and follow it to the intake manifold as well as your search for under-dash issues.

hope this helps.

good luck.

jon_89

If I remember correctly a common issue is a vacum line that runs under the battery to the vacum canister that battery acid eats. May want to check that.

sandfish88

yes happend to my GMC and my jeep. I think the desert makes batteries sick.

XJcountry

Make sure to check all your vacuum lines in the engine bay, if all those are good just check to see if you have vaccuum at all the lines by your dash. My jeep had the same problem, and it was the vaccuum line coming out of the resevoir on the passenger side that had broken, my jeep also has cruise control and that was also not working. I fixed that line and both my problems were fixed.

DFlintstone

Yea, that reservoir bottle down behind the bumper is a good place to check. Guess there are two lines? One large and one smaller, that run from around the E-vac canister to down there. Besides cracking, that bottle can get knocked around or have the lines get messed up.

Hopefully you will hear a hiss at some point. With my reservoir working, I can hear my leak in the dash hiss for a few seconds after I turn it off. (I've looked for it a few times, I guess the defroster diaphragm is way the **** in there!)

I'm hopping to get a better look when I have my radio out. IIRC with it out you can reach a bit back there. Come to think of it, maybe the glove compartment comes out? That might help.