bad blend door?
Thread Starter
|
New User
Joined: Dec 2013
Posts: 18
Likes: 0
bad blend door?
Hi I'm new to this site but have read a lot of threads on heating and blend door. I have a 97 f150 with 4.6 supercab . I have heat just not real hot. Replaced thermostat twice and still nothing better . So for chits I turned the ac on max ( removed pump last week) and had hot heat but every now and then I d hear a door move but still hot hotter than the normal settings .don't think or hope its the blend door. Motors not factory and vacuum hoses behind battery by firewall kinda hacked together but what I've been able to find looked righ.
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
vacuum hoses and cylinders are to move doors in the ducts to point the air at the defrost, dash or floor. There is one MOTOR operated door under the radio, above the transmission hump. This "blend door" is variable sop you can dial in the exact temp you want in the truck. It blends the cool air that bypasses the heater, with air from the heater core to get the right temp. The vacuum direction doors are OPEN- CLOSE - not variable. TAke the plastic dash off above the transmission hump to get a better view of the motor and drive.
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
well, i really dont understand how the AC on max is getting heat. What "max" does is close another damper so you go no outside air, just recirc the cab air. I assume thats what your getting when you say "better heat"... and no, that will not hurt.
Thread Starter
|
New User
Joined: Dec 2013
Posts: 18
Likes: 0
Blend door sounds to be going full to each side and all other doors function right going to use therm gun and try to get temps off everything ? Almost was hoping it was blend door just to know.
Trending Topics
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
Another option is the "outside air door" i was talking about. Probalby in front of the glove box. If it leaks bad, you get cold air dumping onto the passenger side floor. When you go to "max AC" the door is suppose to close all the way and recirc inside air. Normally when the door is bad, you get lots of cold air onto the passenger floor.
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
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
Thread Starter
|
New User
Joined: Dec 2013
Posts: 18
Likes: 0
Took temp reading on heads by each exhaust port and have about 250 give or take a few degrees but at thermostat housing and metal pipe at back of motor for heater core about 95 to 105 tops. The radiator is only about 50 or so .. could I be having a pump issue . Whether .the fact of shutter which I need to poke around here a little more I read last night about bad plugs or wires could be a possible added culprit of this also. Sounding almost like full coverage and a joy ride if only .
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
top hose to radiator should be thermostat temp... close to 200 degrees. What does your dash gauge say for temp ? Feel the heater hoses. One should be HOT inlet and the out should be quite a bit cooler after you transfer heat to the air. If water pump or fan dont work, you sould eventually overheat... again, look at dash guage.
Thread Starter
|
New User
Joined: Dec 2013
Posts: 18
Likes: 0
Dash guage is about 3/8 up normal top hose temp only about 90 95. Temp at heads by each exhaust port about 250 lower thermostat housing about 120 . Dash gauge does rise up from cold don't believe its broke.
Thread Starter
|
New User
Joined: Dec 2013
Posts: 18
Likes: 0
Found water pump has excess play going to replace this weekend just dealing with a lot of issues with truck since I loaned it to father in law for a long trip , from this heat when u need it most , shutter and shake at 40 to 65 ,( plugs hopefully), and noticed no cel today so had codes checked of course p0442 and p0401 . Pretty much believe I'm gonna be through whole vehicle this year.
Thread
Thread Starter
Forum
Replies
Last Post
Dragoness1975
Escape & Escape Hybrid
3
Jun 17, 2013 10:48 PM
joners
1997 - 2006 Expedition & Navigator
6
May 24, 2010 06:07 PM
Charlie Foster
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
2
Sep 23, 2003 12:58 PM