on my '08 lmt, my 2nd row ceiling air vents have a mind of their own.

Now you have the button 'REAR', which toggles the 2nd row's controls.. that is off. Now when I put the air on and adjust the fan speed, and /or the fan speed for the rear, the 2nd row (not 3rd) ceiling air vents sometimes have air flow, and sometimes don't.

What is the deal here? They should be flowing air in tune with either the main fan or the rear fan? which I don't know.. but right now they are sometimes off and sometimes on.. what gives? I'm ready to bring it into the dealer...

 

I found the same thing a day ago. It seems tied to temp. I had the front no a/c at 60f. The rear at 90f. It was only coming out of the floor under my seat towards the rear feet. I turned the front temp to 80 and it started coming out of the vents. WHo knows!

 

man... that would be really strange. But yet the 3rd row ceiling vents are in perfect sync with the fan controls. I'm going to stop by a dealer - but i'm guessing they'll have no idea... don't you love the knowledge they posess of how the trucks actually worK?

I'm sensing a flaw...

 

On my 07 the AC system has a mind of its own at times and does some strange things. When this happens I switch the AC system off then back on, then it starts working right (or the way I think it should any way).

See the other postings on here as many other people are having problems with their AC system as well.

 

I played around with the rear air/heat this weekend. I found that if you put the rear air on the highest heat setting, it only comes out on the floor, if you take the heat down one notch from highest, it goes to the roof vents. I will mess with it some more. doesn't seem right to me. Max heat should come out of all vents.

 

I discovered the same problem last night with my 07 xlt. I had it working once not sure how but went out today and could not get air out of the ceiling vents with the rear button pressed. However there was flow coming out behind the second row seating on the floor???? What gives???

 

I was told only A/C comes out of the ceiling vents.

 

I was a bit frustrated with this on my EL also. Coming from an Excursion where "I" got to pick where the air came from, I found it a bit odd that these Expy's wont let you choose. It would seem that the truck picks which way it thinks is best for the conditions... much like how it adjusts the air flow from the dash in the auto setting.

Its a pain for me, because with the seats folded and the back end set up for my three big dogs, the "floor" vent between the 2nd and 3rd row seats is obstructed.

You have a little better control if you use the rear passenger controls rather than the dash controls. With the temp control **** set about in the middle, you get air overhead.

 

I actually had my truck in two weeks ago for that reason (don't use heat often in San Diego) because no hot air would come out of the top vents. It took them all day to figure it out, but they discovered (duhhhh!) cold air exchange is on the top, hot air is only on the bottom, exactly as designed.

 

Hot air will come out of the top rear vents, just not on the hottest setting.

 

So with the "rear" button pressed I should be able to get air out of the top vents if I move the thermostat to between cold and cold/hot?

Thanks

 

Its not so much that you are getting hot air out of the top, its just the controls are set to "warm", which kind of gives you cool air from the top, and warm air from the bottom, so I suppose it may be warmer than ambient but not true heated air.