Ok I only get luke warm air when my heat is on. When I change the temp control it will go colder, but not warmer. A/C worked great in the summer. Both heater hoses about the same temp. Temp gauge about where it should be. Coolant level is correct. What should I be checking? Actuater, blend door,,,,? The temp stays a consistent luke warm so I am not finding a good answer by searching.
1997 F150

 

Change tstat, flush the heater core and it will work. Had the same issue, now I got great heat, my heater core was blocked

 

If the heater core is blocked wouldnt one heater hose be cooler?

 

Typically one hose would be cooler if the core is plugged. Have seen the heater bypass itself. Most heater cores have a block between the hoses but can break off or rot away! Maybe the coolant is only going thru a few rows of the core. Both hoses to the core should be blistering hot going to the core! If they are I would check the actuator movement. At the center of dash behind the lower black trim panel. Make sure it looks to move all the way or check by unbolting the actuator and physically move the door stop to stop. See what kind of heat you get then. Report back. Good luck!

 

If your getting luke warm heat just like I had then it is blocked, not completely, but enough to keep coolant from flowing through the right way.

 

If both your heater hoses are hot to the touch, it won't be the heater core being plugged. If flow goes thru without restriction, then it's not the core.

Check the blend door. With the A/C'd trucks, the doors break at the mounting joint. It keeps part of the cold air coming in from the outside, so it never gets hot.

Check the forum for the blend door fix. You will find many ways to repair yours without having to remove the dash (pain in the butt). You'll see numerous pics of ways to get into repair the door if this is your problem.

My home page has a picture schematic of the AC heater doors and motors that may give you some in-site to fixing your problem. If you don't have a service manual, PM me, and I'll email you the section on AC repairs. I've sent this to a couple guys who have fixed their systems that were doing your description of your problem. Good luck

 

He said when he turned the **** it got colder, so the door works. It's a process of elimination, the easiest and cheapest route is flush the core, if that don't work then it's something else, but for me I had Luke warm heat as well, changed my tstat, then flushed the system and then the core and bits and pieces of rust and crap came out, hooked it back up and now I have heat.

 

That is correct, that is the cheapest way, but he also said that both hoses were hot. I would of went with that, but it happens too often with this truck. If the door is broken on one side (I don't remember which side, but one will still work partially and the other wont' change anything), it can still partially cover the opening and give you luke warm air and will get colder when it is turned to cooler.

This is a problem that happens often enough with these years, that there are so many threads in the forum. We changed quite a few of these at the dealerships I worked at. Ford never issued a recall, but at one time we had a TSB on the problem. Of course that was 10 years ago, but still even then we had the problem. Now these trucks are older and the plastic more brittle.

 

Before you go through that process of cutting the dash out... Or takeing the dash out... Take the actuator motor out... and try to turn the little stud on the motor... If that thing spins like its stripped out...

I just went through this whole ordeal on my 02... But i didnt check the motor first... I cut the dash out...(good videos on youtube...look up heater treater blend door) ... You dont need there door...

If you find out you need a door.. Autozone sells them for around 27 dollars.. Make sure it has a metal collar on the bottom hindge .. The early ones didnt... The new ones have a metal sleeve.. Thats the one you need..

 

i checked my door first and it was still good as was the accuator so i flushed SEVERAL TIMES and only a nominal improvement so i had the heater core replaced at a local shop ($750 job) and the heat is great now. The only thing anyone could come up with was that the heater core had bypassed itself like TRD-toy said so there ya go!