99 F150 Heater Control Problem?
Junior User
Joined: Nov 2008
Posts: 61
Likes: 0
Hi all. short bio here.
99 F-150, 4.2L, auto, 2WD 177K miles
Saw the heater issue and our F-150 has no heat. Read this thread and FIXED IT!!!!!!!
Pulled the **** off that moves from warm to cool and it was cracked on the inside. The shaft was not moving when I turned the ****. I put the needle nose on it and turned it clockwise and had the truck running.
Warm air!!! YAY!!
Thanks to all FTE people!
99 F-150, 4.2L, auto, 2WD 177K miles
Saw the heater issue and our F-150 has no heat. Read this thread and FIXED IT!!!!!!!
Pulled the **** off that moves from warm to cool and it was cracked on the inside. The shaft was not moving when I turned the ****. I put the needle nose on it and turned it clockwise and had the truck running.
Warm air!!! YAY!!
Thanks to all FTE people!
New User
Joined: Jan 2012
Posts: 23
Likes: 0
From: Portland, Oregon
I am having similar problems with my 99 F150 and the heater control. I've read a lot of posts about blend doors and actuators but I'm not sure that is the problem. Thought I would post for some more advice. I checked and double checked the **** and I am pretty sure there is no problem with it.
I know the door is supposed to be electronically controlled, but it sure seems to be somewhat dependent on vacuum. When I start the truck in the mornings, even after the temp gauge shows the truck is plenty warm, it will only blow cold air. If you get on it pretty hard leaving a stop light you can feel the air coming out of the vent getting a little warmer and when stopping at the next light the air gets cooler. It never gets as cool as it was before the last stoplight and so eventually the air gets really warm and doesn't cool down at an idle. Of course by this time I am just about to work.
Also, once the air does get really warm, the control switch doesn't seem to have any effect on the temperature. You can move it to a cooler setting but the air stays warm, even on AC. Seems like bumps and potholes also effect the air temp sometimes.
I think the actuator is working because I can hear the motor when switching the control from cool to warm or warm to cool. Is the actuator locatred behind the glove box on F150's like is posted in the blend door fix? The actuator motor noise seems to coming from somewhere in the middle of the dash, just above the hump in the floorboard.
One more thing, when the AC is on and blowing cold air, if you hit the gas pretty hard (like dropping down into passing gear) you can hear a clunk in the dash and suddenly the air from the AC gets hot.
Any suggestions, advice or comments will be appreciated!
Thanks in advance,
Kevin
I know the door is supposed to be electronically controlled, but it sure seems to be somewhat dependent on vacuum. When I start the truck in the mornings, even after the temp gauge shows the truck is plenty warm, it will only blow cold air. If you get on it pretty hard leaving a stop light you can feel the air coming out of the vent getting a little warmer and when stopping at the next light the air gets cooler. It never gets as cool as it was before the last stoplight and so eventually the air gets really warm and doesn't cool down at an idle. Of course by this time I am just about to work.
Also, once the air does get really warm, the control switch doesn't seem to have any effect on the temperature. You can move it to a cooler setting but the air stays warm, even on AC. Seems like bumps and potholes also effect the air temp sometimes.
I think the actuator is working because I can hear the motor when switching the control from cool to warm or warm to cool. Is the actuator locatred behind the glove box on F150's like is posted in the blend door fix? The actuator motor noise seems to coming from somewhere in the middle of the dash, just above the hump in the floorboard.
One more thing, when the AC is on and blowing cold air, if you hit the gas pretty hard (like dropping down into passing gear) you can hear a clunk in the dash and suddenly the air from the AC gets hot.
Any suggestions, advice or comments will be appreciated!
Thanks in advance,
Kevin
...as soon as it stops snowing.
New User
Joined: Jan 2012
Posts: 23
Likes: 0
From: Portland, Oregon
Oh, BTW - long time Ford truck owner, first time poster.
My first vehicle was a 78 Courier packing a 2.3 Pinto-powerhouse that I rebuilt when I was 15 (~1990).
Since then, I've owned 4 Rangers, an Explorer, an Escape, and am currently on my 4th F150.
The biggest problem I had with any of them was a stuck thermostat.
My first vehicle was a 78 Courier packing a 2.3 Pinto-powerhouse that I rebuilt when I was 15 (~1990).
Since then, I've owned 4 Rangers, an Explorer, an Escape, and am currently on my 4th F150.
The biggest problem I had with any of them was a stuck thermostat.
Junior User
Joined: Dec 2011
Posts: 74
Likes: 0
From: illinois
take the finish cover off your floor register, take a 2 inch hole saw and drill a opening you can see your flapper through that, the flap on mine was broke where it hindged, took a screw on a extension and screwed into the hindge for a quick fix, use aluminum duct tape over the hole then replace cover
New User
Joined: Jan 2012
Posts: 23
Likes: 0
From: Portland, Oregon
take the finish cover off your floor register, take a 2 inch hole saw and drill a opening you can see your flapper through that, the flap on mine was broke where it hindged, took a screw on a extension and screwed into the hindge for a quick fix, use aluminum duct tape over the hole then replace cover
New User
Joined: Jan 2012
Posts: 23
Likes: 0
From: Portland, Oregon
I've noticed something strange, and it's happened twice that I know of... My temp gauge shows mid-range (190 degrees?) and I have cold air. Then all of a sudden, temp spikes up to 7/8 range (220?) and then drops really quickly back to mid. Hot air comes with the drop in engine temp and stays hot after that. The spike makes me nervous, but my initial guess is that it's just low on fluid.
So I'm thinking it must have to do with flow through the heater core??
And thanks, Racerguy.
So I'm thinking it must have to do with flow through the heater core??
And thanks, Racerguy.
New User
Joined: Jan 2012
Posts: 23
Likes: 0
From: Portland, Oregon
UPDATE: I was about 1/2 gallon low on coolant. Topped it off, and my heater works fine. It was just an air bubble.
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New User
Joined: Jan 2012
Posts: 2
Likes: 0
So... I'm pretty sure my prob IS the control ****. Now the queston, How do you pull the **** off? It's slicker'n ....& I can't really get a grip on it. I don't want to have to resort to pliers, cuz I don't want to mar the ****. TY in advance
Hotshot
Joined: Aug 2002
Posts: 12,679
Likes: 15
From: BC, Canada
Welcome to the forum 
If you have to replace the **** anyway you can just pull it off with pliers.
If you don't want to mark it up with the pliers you could wrap some masking or electrical tape around it for the pliers to grip.
If you have to replace the **** anyway you can just pull it off with pliers.
If you don't want to mark it up with the pliers you could wrap some masking or electrical tape around it for the pliers to grip.
New User
Joined: Oct 2006
Posts: 11
Likes: 0
hot air sometimes/cold the next time
Sometimes it blows hot air ,next time it blow cold .I took out the blend door motor, plug it back in to connector and is not working,motor will not turn the the shaft,went to the store with the motor out it blew hot air all the way there,returned home with cold air.HELP I have 99 f250 lite duty 4.6 4x4
Anyone?
Fleet Mechanic
Joined: Apr 2008
Posts: 1,724
Likes: 2
From: Vancouver BC Canada
I did a search on this forum recently for weak heat and found a link for a blend door fix. This company has a kit you can buy, with how-to-videos.
http://www.heatertreater.net/index.html
FYI I just today discovered that my problem was the white plastic shaft behind my temperature **** was stripped.
http://www.heatertreater.net/index.html
FYI I just today discovered that my problem was the white plastic shaft behind my temperature **** was stripped.
Last edited by BCHauler; Nov 23, 2012 at 07:58 PM. Reason: added link
New User
Joined: Nov 2012
Posts: 3
Likes: 0
My 1994 F150 heater fan runs, never warms up. I checked thermstat/ ok. I notice the temp guage stays max cold even after truck warms up. I turn the truck off and the temp indicator rises to normal warm up indication. Truck starting is different- Starts normal, then hard to start after warm up/ intermittant. I suspect a sensor, any ideas?
The temp indicator indication along with the no hot air as me scratching my head.
The temp indicator indication along with the no hot air as me scratching my head.