So, I understand that there are the controls by rear view mirror to be reached by the driver, and controls behind the drivers seat (on ceiling) to be reached by the passengers. My issue is, the controls in the rear were deleted to make way for a DVD player. The temp dial on the controls for the driver do nothing to change the rear temp. Last summer, the AC worked in the rear and I never gave it any thought except to be curious how it was being controlled, and I suspected perhaps it wasn't, and I'd have to deal with it one day when I didn't want AC. Then winter hit, and the rear blew hot, so I began to suspect that it was linked to the temp controls for the front, controlled by the dash module. Well, as it's been 55ish degrees, I've been turning the AC on in the front, which will blow cold, and the rear will blow cold then hot, sorta on a mind of its own. Now that it's been in the 70s, having the rear on stays cold and in the mornings, where its 50ish, it will swing cold to hot, hot to cold, but later in the day it stays steady cold.

I now suspect that the rear temp is being controlled by ambient exterior temp, in some form of AUTO, like the front controls are (making an assumption here about the front also). Is that a thing for the rear, where ambient temp could control output, or am I going to have to figure out what was done to delete the rear controls and go from there?

 

Confirmed the weird temp control of the rear today. When I left my house, it was 47ish degrees, and the rear blew heat until I couldn't bear it anymore. On the way home, 77ish degrees, ice cold for 30 minutes, no changes in front (dash) temp control. It's clearly not broken, considering that it works when I REALLY want it to, as opposed to everything else that breaks in our lives where it doesn't work when we want it to most.....I just don't know how it has a mind of its own in regard to the temp outside (or maybe inside the truck) for the rear only.

 

You'd have to look at pics online cause I do not know for certain, but even though you are probably electronic climate controls in the front, I think all Excursions still had analog controls for the rear including the master slave controls above the rear view mirror, and the slave controls for the second row.

 

That's what I thought too, guess if I want to get manual control over the rear temp then ill have to tear it apart and trace wires, because whatever controlling my temp is something other than factory. For now, I guess I'll be happy that it blows cold when it's hot outside

 

Another day of confirmation - truck was a hot box in the morning, about 49* on morning ride, and 'bout froze to death in the afternoon, 77* outside and didn't touch any controls

 

Similar issue.

https://www.ford-trucks.com/forums/1...ispreloading=1

 

Thanks, yes that is similar, but my issue goes a bit further in that I have no idea what is controlling the temp in the rear. The temp **** next to the rear view mirror does nothing, but somehow it miraculously knows when its hot and cold out to switch from ac to heat w/o changing the dash temp also

 

Time to post pics of your rear ceiling setup.