Heater anomaly . . .
Thread Starter
|
Mountain Pass
Joined: Oct 2011
Posts: 208
Likes: 3
From: Cheyoming
Heater anomaly . . .
'01 F350. Winter setting in in the Rockies and am having a strange heater problem.
Engine temp is up and adiquit to heat cab, but cold air is coming out of vents. I've tried rotating the temp control, set it to "medium" heat, then back up again.
Then next time I get in, the heat is coming out. . . . or not. Not predictable.
I've had the truck for 7 years and am very familiar with how the controls work.
As if a valve or vent isn't opening. Are they run by vacuum?
WT*?!
Engine temp is up and adiquit to heat cab, but cold air is coming out of vents. I've tried rotating the temp control, set it to "medium" heat, then back up again.
Then next time I get in, the heat is coming out. . . . or not. Not predictable.
I've had the truck for 7 years and am very familiar with how the controls work.
As if a valve or vent isn't opening. Are they run by vacuum?
WT*?!
Laughing Gas
Joined: Nov 2010
Posts: 1,193
Likes: 2
From: D.C. but heart's in TEXAS
You may have a broken or slightly broken blender door, which is located behind the glove box. Do a search on here on how to diagnose (you're going to need a small angled mirror), and how to fix.
May not be the issue, but...
May not be the issue, but...
Hotshot
Joined: Jul 2008
Posts: 12,782
Likes: 2,142
From: N.GA Mountains
The Lariats and Excursions do have a valve, but it only stops flow from heater core when MAX AC is selected. You can verify the hoses to heater core are getting hot and narrow it down to a blend door pretty easily.
Thread Starter
|
Mountain Pass
Joined: Oct 2011
Posts: 208
Likes: 3
From: Cheyoming
Trending Topics
Thread Starter
|
Mountain Pass
Joined: Oct 2011
Posts: 208
Likes: 3
From: Cheyoming
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Post Fiend
Joined: May 2009
Posts: 5,470
Likes: 3
From: Pea Ridge, AR
The temperature blend door is not vacuum actuator, the panel vent control is. The blend door is an electric actuator. I've never seen the electrical portions fail personally, but the square drive or door pin itself I have seen break, especially with them being plastic.
The actuator is pretty easy to get to, behind the glovebox, you should be able to remove the couple of screws holding it in, and try the temp control, to see if the actuator moves, if it does, look at the door itself, down in the hole the actuator connects to, and make sure it's not broken.
The actuator is pretty easy to get to, behind the glovebox, you should be able to remove the couple of screws holding it in, and try the temp control, to see if the actuator moves, if it does, look at the door itself, down in the hole the actuator connects to, and make sure it's not broken.
Freshman User
Joined: Jan 2005
Posts: 27
Likes: 0
I'm dealing with the same issue on my '99 350. I have hot heater hoses, opened up the fan box and watched the blend door move back and forth with the temperature selector. Is it possible to have an intermittant problem with the blend door actuator. Also the a/c comes on with the selector switch in all positions except the first position to the left and the second position to the right. Is that normal or could the a/c be coming on cooling the air. Sorry to hijack the thread but it sounds like the same problem.
Laughing Gas
Joined: Nov 2010
Posts: 1,193
Likes: 2
From: D.C. but heart's in TEXAS
The issue with the blend door is that typically the piece of plastic gets broken, so the mechanism is turning, but the door doesn't actually move. It's more common that it gets stuck where it is allowing heat in, but sometimes it breaks where it is closed and won't allow heat in. Here's a link to photos, etc.
https://www.ford-trucks.com/forums/1...full-cool.html
If your door is broken, here's the Dorman part:
http://www.dormanproducts.com/p-11567-902-207.aspx
https://www.ford-trucks.com/forums/1...full-cool.html
If your door is broken, here's the Dorman part:
http://www.dormanproducts.com/p-11567-902-207.aspx
Posting Guru
Joined: Oct 2012
Posts: 1,910
Likes: 2
From: Hat Creek Ca
Yes the A/C is on with everthig except "vent" on my '01 and '02 ranger. It normally runs with the heater and especially the defroster. On defrost so the air goes though air dryer. Otherwise you get warm wet air on your windshield and need to carry a bag of bullduram to clean the inside like I did in my '50 Chevy