Need A/C help
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Tuned
Joined: Jul 2002
Posts: 462
Likes: 5
From: Kansas City, Mo
Need A/C help
2000 Excursion 142,000 miles. A/C runs fine on Max setting but any thing else and it just blows hot air. Tried searching but maybe I wasn't using the right search terms cause I couldn't find squat! Any help is appreciated thanks, John
Senior User
Joined: Mar 2004
Posts: 150
Likes: 0
The fact that it works on max tells me that the compressor, charge, and compressor clutch are okay. I would take a guess that something is going wrong in the dash, behind the climate control. But, that is just a guess.
Posting Guru
Joined: Oct 2003
Posts: 1,198
Likes: 2
From: Tulsa, OK
Yes. Check all the vacuum lines. Maybe one is cracked or slipped off. There should be a manifold connection on the V10. Pull this off. Use a hand vacuum pump (or suck on it) to see if it can "hold" a vacuum.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
I believe the Excursions had, from the factory, what us truck guys add on as a mod.
It's a vacuum-controlled valve in the heater-hose line that shuts off coolant flow to the HVAC box during MAX mode. I suspect that is a major clue here.
When you're in MAX mode, there is no "heater" action inside the box, and you get cold. Once you leave MAX mode, the coolant again flows to the box, and you get heat. There's more heat available from the heater than there is cold from the A/C, so you get warm.
What's supposed to happen during A/C is the blend door should direct most of the air flow through the evaporator coil, and not through the heater core (unless, or course, you WANT it at eighty degrees on a hot day). If the blend door isn't working properly, it goes through the heater core instead. Sound like what's happening?
So, I suspect your blend door isn't operating. It's vacuum controlled, and there are lots of threads (though not many recently) on fixing a blend door problem.
Like always, "Search" is your friend.
"blend door" is the subject to plug in.
The guys posting above have steered you in the right direction.
I've attached a couple of PDFs for you to read to get an idea of how the system works.
Pop
It's a vacuum-controlled valve in the heater-hose line that shuts off coolant flow to the HVAC box during MAX mode. I suspect that is a major clue here.
When you're in MAX mode, there is no "heater" action inside the box, and you get cold. Once you leave MAX mode, the coolant again flows to the box, and you get heat. There's more heat available from the heater than there is cold from the A/C, so you get warm.
What's supposed to happen during A/C is the blend door should direct most of the air flow through the evaporator coil, and not through the heater core (unless, or course, you WANT it at eighty degrees on a hot day). If the blend door isn't working properly, it goes through the heater core instead. Sound like what's happening?
So, I suspect your blend door isn't operating. It's vacuum controlled, and there are lots of threads (though not many recently) on fixing a blend door problem.
Like always, "Search" is your friend.
"blend door" is the subject to plug in.
The guys posting above have steered you in the right direction.
I've attached a couple of PDFs for you to read to get an idea of how the system works.
Pop
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,732
Likes: 2,661
From: SE Florida
Replacing the blend door with the factory part is expensive and the new one will fail, too. I installed a Heater Treater on several vehicles. It's a MUCH better part and it's easier to install, too.
They don't list one for Excursion, but they do for F250+. I think they are the same, you many want to contact them to be sure.
F250+ - Ford
They don't list one for Excursion, but they do for F250+. I think they are the same, you many want to contact them to be sure.
F250+ - Ford
Excursion Fleet Manager
Joined: Dec 2009
Posts: 1,791
Likes: 5
From: Green Oak, MI
Replacing the blend door with the factory part is expensive and the new one will fail, too. I installed a Heater Treater on several vehicles. It's a MUCH better part and it's easier to install, too.
They don't list one for Excursion, but they do for F250+. I think they are the same, you many want to contact them to be sure.
F250+ - Ford
They don't list one for Excursion, but they do for F250+. I think they are the same, you many want to contact them to be sure.
F250+ - Ford
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