I have searched the forum and could not find a solution to my problem.


2001 F150 Screw 5.4L, 4x4.


Had a leaking heater core back in the summer and had it replaced. Everything went fine. Just turned cool here and first time I turned the heater on, it only blows cold air. Checked the fluid level and it is full. Got the engine up to operating temperature and turned the temperature control on to the highest setting. Blows cold air. Both of the heater hoses are warm to hot to the touch. All of the controls are working properly, ie, panel, defrost, floor, all blowing cold air. All of the fan speeds working like they should, checked fuses, all ok.
I ran it with the cap off for about 30 minutes to make sure there was no air trapped.


I am stumped at this point.


Any help will be greatly appreciated.

 

Maybe check the damper in the duct that blends the cold and hot air , it's probably not moving and opening to the hot duct when you turn the *** too hot. Also make sure the **** itself isn't broken so you think your turning the **** but it's actually not turning the dial due to the tabs broken on the ****. I've seen both happen. Oh yeah also check the vent going past the heater core and make sure that it's not blocked

 

Thanks for the advice, I will take a look at it.

 

A few years before I had the same problem. I replaced the a/c switches on the dash (the fan speed and hot and cold switch) and my problem was fixed. I bought the part on ebay really cheap. However, what was mentioned above about the blend door is a common problem. When this happens what alot of owners do is remove glove compartment and cut a small square hole 4inch by 4inch or so to have access to door blend in order to avoid removing dashboard. There are some youtube videos that you could look up.

 

FYI those asterisk marks are not me swearing they editing the word that means dials , the things you use to change the temp and other settings I know you guy know but just incase someone thinks I'm saying something bad I didn't

 

Well, I watched all the youtube videos I could find and started the project to get the actuator motor out. None of them show exactly how the plastic plenum under the actuator motor is removed, there are supposed to be 3 screws. I found the ones on the left and right sides and there is supposed to be one on the backside. Can't find it anywhere. I know it has to be hidden in there somewhere like the other ones were. Does anyone know or can help be locate it? Wife took over the truck from me and she says she has to have the heat.

 

Still needing help.

 

Before you go too deep, did you check the vacuum line that goes through the fire wall? If this is disconnected or leaking air, your blend doors will not work.

 

Vacuum lines were intact. Already have everything disconnected except for the one screw that is supposed to be behind the plenum. Have to get it out before I can remove and test the actuator motor. Thanks for replying.

 

Heat is more important than cold.. If you cant figure it out, follow 1968dave's suggestion. I had to do mine the same way, I can care less about a/c-fresh air is more enjoyable anyway.