Hello all,
I have a 2005 navigator. Like the title says my A/C is stuck in defrost mode. I did a good deal of searching and read the culprit may be a vacuum leak under the hood near the battery.

I go under there yesterday and lo and behold I found a broken tube! *Its under my finger. I looked and looked but I cant find the other end and was hoping someone could provide a little insight.

Also to the left there is a little port that looks like it should have a cap or hose on it. Does anyone know what should go there? Yes, I already tried connecting these two via a vac hose but nothing happened.

I'm going out of town tomorrow if you can offer anything I'm willing to listen.

Here is a quick video of the exact location
And a pic



Thanks

 

I'm fairly certain that your mode door is controlled by an electric actuator. They can fail, not allowing you to select which vents to use. I know in the F150's, you have to remove the center bezel and radio, and drop the glove box to access the actuator. It will be located in between the glove box and radio. Sometimes they fail because foam from the mode door falls off and jambs the door, other times they just fail for no apparent reason.
The vacuum line you're looking at appears to be part of the 4wd IWE system. If there are no other lines open or broken, then it's going to be the vent line for the passenger side IWE actuator.

 

Sorry for the late response. I noticed the number of views so it seems i wasn't the only one with this problem.

To be honest this problem magically fixed itself one day. It happened right after I replaced my alternator. I got no warning lights or dash indications that the alternator was going bad but over time it started to drain my battery. I hooked up the multimeter and was only getting about 11-12 V.

I replaced the alternator and the battery terminals (just being thorough) then as soon as I start the truck the vents work!

It seems these trucks are very particular about there voltage requirements. Any dip can make all sorts of things act up.

And Lewissa81 you are right that little hose is just for the IWE actuator.

Thanks and I hope this helps someone